Method for transmitting and receiving signal in wireless communication system, and apparatus for supporting same

ABSTRACT

The present disclosure relates to a wireless communication system. Specifically, provided is a method and an apparatus for supporting same, the method comprising the steps of: obtaining random access procedure-related message A, message A including a physical random access channel (PRACH) preamble and a physical uplink shared channel (PUSCH); transmitting message A; and receiving random access procedure-related message B as a response to message A, wherein the PUSCH comprises a demodulation reference signal (DM-RS), and PRACH preamble is mapped to (i) one or more DM-RS ports and (ii) one or more DM-RS sequences on the basis of indices of respective (i) one or more DM-RS ports and indices of respective (ii) one or more DM-RS sequences.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/431,021, filed on Aug. 13, 2021, which is a National Stageapplication under 35 U.S.C. § 371 of International Application No.PCT/KR2020/002155, filed on Feb. 14, 2020, which claims the benefit ofU.S. Provisional Application No. 62/842,612, filed on May 3, 2019,62/806,624, filed on Feb. 15, 2019, and 62/806,622, filed on Feb. 15,2019. The disclosures of the prior applications are incorporated byreference in their entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a wireless communicationsystem, and more particularly, to a method and apparatus fortransmitting and receiving a signal in a wireless communication system.

BACKGROUND

Wireless access systems have been widely deployed to provide varioustypes of communication services such as voice or data. In general, awireless access system is a multiple access system that supportscommunication of multiple users by sharing available system resources (abandwidth, transmission power, etc.) among them. For example, multipleaccess systems include a code division multiple access (CDMA) system, afrequency division multiple access (FDMA) system, a time divisionmultiple access (TDMA) system, an orthogonal frequency division multipleaccess (OFDMA) system, and a single carrier frequency division multipleaccess (SC-FDMA) system.

As a number of communication devices have required higher communicationcapacity, the necessity of the mobile broadband communication muchimproved than the existing radio access technology (RAT) has increased.In addition, massive machine type communications (MTC) capable ofproviding various services at anytime and anywhere by connecting anumber of devices or things to each other has been considered in thenext generation communication system. Moreover, a communication systemdesign capable of supporting services/UEs sensitive to reliability andlatency has been discussed.

As described above, the introduction of the next generation RATconsidering the enhanced mobile broadband communication, massive MTC,Ultra-reliable and low latency communication (URLLC), and the like hasbeen discussed.

SUMMARY

Various embodiments of the present disclosure may provide a method andapparatus for transmitting and receiving a signal in a wirelesscommunication system.

Further, various embodiments of the present disclosure may provide amethod and apparatus for performing a 2-step random access channel(RACH) procedure in a wireless communication system.

Further, various embodiments of the present disclosure may provide amethod and apparatus for multiplexing physical uplink shared channels(PUSCHs) and/or mapping a demodulation reference signal (DM-RS) inmessage A (MsgA) to support a 2-step RACH procedure.

Further, various embodiments of the present disclosure may provide amethod and apparatus for multiplexing an RACH occasion and a PUSCHoccasion in MsgA for a 2-step RACH procedure in a wireless communicationsystem.

Further, various embodiments of the present disclosure may provide amethod and apparatus for configuring MsgA depending on whether an RACHoccasion is allowed to be shared between a 2-step RACH procedure and a4-step RACH procedure in a wireless communication system.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the various embodiments of the presentdisclosure are not limited to what has been particularly describedhereinabove and the above and other objects that the various embodimentsof the present disclosure could achieve will be more clearly understoodfrom the following detailed description.

Various embodiments of the present disclosure may provide a method andapparatus for transmitting and receiving a signal in a wirelesscommunication system.

According to various embodiments of the present disclosure, a method ofa user equipment (UE) in a wireless communication system may beprovided.

In an exemplary embodiment, the method may include obtaining a message Arelated to a random access procedure, the message A including a physicalrandom access channel (PRACH) preamble and a physical uplink sharedchannel (PUSCH), transmitting the message A, and receiving a message Brelated to the random access procedure in response to the message A.

In an exemplary embodiment, the PUSCH may be transmitted in at least onePUSCH occasion among consecutive PUSCH occasions in a frequency domainand a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained among atleast one preconfigured PRACH preamble,

In an exemplary embodiment, the PUSCH may include a demodulationreference signal (DMRS).

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

In an exemplary embodiment, the at least one PRACH preamble may bemapped to (i) the at least one DMRS port and (ii) the at least one DMRSsequence, based on (i) the index of each of the at least one DMRS portbeing considered in ascending order and then (ii) the index of each ofthe at least one DMRS sequence being considered in ascending order.

In an exemplary embodiment, a maximum number of DMRS ports may be 4based on the DMRS being configured in one orthogonal frequency divisionmultiplexing (OFDM) symbol.

In an exemplary embodiment, the PUSCH may be transmitted based on amodulation and coding scheme (MCS) level associated with a random accesspreamble identifier (RAPID) of the PRACH preamble.

In an exemplary embodiment, based on a plurality of frequency resourcesets being configured for the DMRS: the DMRS may be transmitted based ona frequency resource set associated with the RAPID among the pluralityof frequency resource sets.

In an exemplary embodiment, the PRACH preamble may be transmitted in atleast one PRACH occasion among PRACH occasions.

In an exemplary embodiment, the PRACH occasions and the PUSCH occasionsmay be multiplexed in time division multiplexing (TDM) based on (i) thePRACH occasions being included in a first slot for the message A and(ii) the PUSCH occasions being included in a second slot for the messageA, and the first slot and the second slot may be different.

In an exemplary embodiment, a time offset may be configured between thePRACH occasions and the PUSCH occasions in the time domain.

According to various embodiments of the present disclosure, an apparatusconfigured to operate in a wireless communication system may beprovided.

In an exemplary embodiment, the apparatus may include a memory, and atleast one processor coupled to the memory.

The at least one processor may be configured to obtain a message Arelated to a random access procedure, the message A including a PRACHpreamble and a PUSCH, transmit the message A, and receive a message Brelated to the random access procedure in response to the message A,

In an exemplary embodiment, the PUSCH may be transmitted in at least oneof consecutive PUSCH occasions in a frequency domain and a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained fromamong at least one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

In an exemplary embodiment, the at least one PRACH preamble may bemapped to (i) the at least one DMRS port and (ii) the at least one DMRSsequence, based on (i) the index of each of the at least one DMRS portbeing considered in ascending order and then (ii) the index of each ofthe at least one DMRS sequence being considered in ascending order.

In an exemplary embodiment the PUSCH may be transmitted based on an MCSlevel associated with an RAPID of the PRACH preamble.

In an exemplary embodiment, the apparatus may communicate with at leastone of a UE, a network, or an autonomous driving vehicle other than avehicle including the apparatus.

According to various embodiments of the present disclosure, a method ofa base station (BS) in a wireless communication system may be provided.

In an exemplary embodiment, the method may include receiving a message Arelated to a random access procedure, obtaining a PRACH preamble and aPUSCH included in the message A, and transmitting a message B related tothe random access procedure in response to the message A.

In an exemplary embodiment, the PUSCH may be received in at least onePUSCH occasion among consecutive PUSCH occasions in a frequency domainand a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained among atleast one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

According to various embodiments of the present disclosure, an apparatusconfigured to operate in a wireless communication system may bereceived.

In an exemplary embodiment, the apparatus may include a memory, and atleast one processor coupled to the memory.

In an exemplary embodiment, the at least one processor may be configuredto receive a message A related to a random access procedure, obtain aPRACH preamble and a PUSCH included in the message A, and transmit amessage B related to the random access procedure in response to themessage A.

In an exemplary embodiment, the PUSCH may be received in at least onePUSCH occasion among consecutive PUSCH occasions in a frequency domainand a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained among atleast one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

According to various embodiments of the present disclosure, an apparatusconfigured to operate in a wireless communication system may beprovided.

In an exemplary embodiment, the apparatus may include at least oneprocessor, and at least one memory storing at least one instructioncausing the at least one processor to perform a method.

In an exemplary embodiment, the method may include obtaining a message Arelated to a random access procedure, the message A including a PRACHpreamble and a PUSCH, transmitting the message A, and receiving amessage B related to the random access procedure in response to themessage A.

In an exemplary embodiment, the PUSCH may be transmitted in at least onePUSCH occasion among consecutive PUSCH occasions in a frequency domainand a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained among atleast one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

According to various embodiments of the present disclosure, aprocessor-readable medium storing at least one instruction causing atleast one processor to perform a method may be provided.

In an exemplary embodiment, the method may include obtaining a message Arelated to a random access procedure, the message A including a PRACHpreamble and a PUSCH, transmitting the message A, and receiving amessage B related to the random access procedure in response to themessage A.

In an exemplary embodiment, the PUSCH may be transmitted in at least onePUSCH occasion among consecutive PUSCH occasions in a frequency domainand a time domain.

In an exemplary embodiment, the PRACH preamble may be obtained among atleast one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence, based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present disclosure are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present disclosure could achieve will be more clearlyunderstood from the following detailed description.

Various embodiments of the present disclosure have the followingeffects.

Various embodiments of the present disclosure may provide a method andapparatus for transmitting and receiving a signal in a wirelesscommunication system.

Further, various embodiments of the present disclosure may provide amethod and apparatus for performing a 2-step random access channel(RACH) procedure in a wireless communication system.

Further, various embodiments of the present disclosure may provide amethod and apparatus for multiplexing physical uplink shared channels(PUSCHs) and/or mapping a demodulation reference signal (DM-RS) in inmessage A (MsgA) to support a 2-step RACH procedure.

Further, various embodiments of the present disclosure may provide amethod and apparatus for multiplexing an RACH occasion and a PUSCHoccasion in MsgA for a 2-step RACH procedure in a wireless communicationsystem.

Further, various embodiments of the present disclosure may provide amethod and apparatus for configuring MsgA depending on whether an RACHoccasion is allowed to be shared between a 2-step RACH procedure and a4-step RACH procedure in a wireless communication system.

It will be appreciated by persons skilled in the art that that theeffects that can be achieved through the various embodiments of thepresent disclosure are not limited to those described above and otheradvantageous effects of the various embodiments of the presentdisclosure will be more clearly understood from the following detaileddescription. That is, unintended effects according to implementation ofthe present disclosure may be derived by those skilled in the art fromthe various embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the various embodiments of the present disclosure,provide the various embodiments of the present disclosure together withdetail explanation. Yet, a technical characteristic the variousembodiments of the present disclosure is not limited to a specificdrawing. Characteristics disclosed in each of the drawings are combinedwith each other to configure a new embodiment. Reference numerals ineach drawing correspond to structural elements.

FIG. 1 is a diagram illustrating physical channels and a signaltransmission method using the physical channels, which may be used invarious embodiments of the present disclosure;

FIG. 2 is a diagram illustrating a radio frame structure in a new radioaccess technology (NR) system to which various embodiments of thepresent disclosure are applicable;

FIG. 3 is a diagram illustrating a slot structure in an NR system towhich various embodiments of the present disclosure are applicable;

FIG. 4 is a diagram illustrating a self-contained slot structure towhich various embodiments of the present disclosure are applicable;

FIG. 5 is a diagram illustrating the structure of one resource elementgroup (REG) in an NR system to which various embodiments of the presentdisclosure are applicable;

FIGS. 6A and 6B are diagrams illustrating exemplary control channelelement (CCE)-to-resource element group (REG) mapping types according tovarious embodiments of the present disclosure;

FIG. 7 is a diagram illustrating an exemplary block interleaveraccording to various embodiments of the present disclosure;

FIG. 8 is a diagram illustrating a representative method of connectingtransceiver units (TXRUs) to antenna elements according to variousembodiments of the present disclosure;

FIG. 9 is a diagram illustrating a representative method of connectingTXRUs to antenna elements according to various embodiments of thepresent disclosure;

FIG. 10 is a simplified diagram illustrating a hybrid beamformingstructure from the perspective of TXRUs and physical antennas accordingto various embodiments of the present disclosure;

FIG. 11 is a simplified diagram illustrating a beam sweeping operationfor a synchronization signal and system information in a downlink (DL)transmission procedure according to various embodiments of the presentdisclosure;

FIG. 12 is a diagram illustrating the structure of a synchronizationsignal block (SSB) to which various embodiments of the presentdisclosure are applicable;

FIG. 13 is a diagram illustrating an exemplary SSSB transmission methodto which various embodiments of the present disclosure are applicable;

FIGS. 14A and 14B are diagrams illustrating an exemplary wirelesscommunication system supporting an unlicensed band, to which variousembodiments of the present disclosure are applicable;

FIG. 15 is a diagram illustrating a DL channel access procedure (CAP)for a transmission in an unlicensed band, to which various embodimentsof the present disclosure are applicable;

FIG. 16 is a diagram illustrating an uplink (UL) CAP for a transmissionin an unlicensed band, to which various embodiments of the presentdisclosure are applicable;

FIGS. 17A and 17B are diagrams illustrating an exemplary 4-step randomaccess channel (RACH) procedure to which various embodiments of thepresent disclosure are applicable;

FIG. 18 is a diagram illustrating an exemplary 2-step RACH procedure towhich various embodiments of the present disclosure are applicable;

FIG. 19 is a diagram illustrating a contention-free RACH procedure towhich various embodiments of the present disclosure are applicable;

FIG. 20 is a simplified diagram illustrating a method of operating auser equipment (UE) and a base station (BS) according to variousembodiments of the present disclosure;

FIG. 21 is a simplified diagram illustrating a method of operating a UEaccording to various embodiments of the present disclosure;

FIG. 22 is a simplified diagram illustrating a method of operating a BSaccording to various embodiments of the present disclosure;

FIGS. 23A to 23D are diagrams illustrating an exemplary configuration ofmessage A (MsgA) according to various embodiments of the presentdisclosure;

FIG. 24 is a diagram illustrating an exemplary resource configurationfor MsgA according to various embodiments of the present disclosure;

FIGS. 25A to 25D are diagrams illustrating an exemplary configuration ofMsgA according to various embodiments of the present disclosure;

FIGS. 26A to 26D are diagrams illustrating an exemplary configuration ofMsgA according to various embodiments of the present disclosure;

FIG. 27 is a diagram illustrating an initial network access andsubsequent communication process;

FIGS. 28A and 28B are exemplary DRX operations according to variousembodiments of the present disclosure;

FIG. 29 is a simplified diagram illustrating a method of operating a UEand a BS according to various embodiments of the present disclosure;

FIG. 30 is a flowchart illustrating a method of operating a UE accordingto various embodiments of the present disclosure;

FIG. 31 is a flowchart illustrating a method of operating a BS accordingto various embodiments of the present disclosure;

FIG. 32 is a block diagram illustrating an apparatus for implementingvarious embodiments of the present disclosure;

FIG. 33 is a diagram illustrating a communication system to whichvarious embodiments of the present disclosure are applicable;

FIG. 34 is a block diagram illustrating wireless devices to whichvarious embodiments of the present disclosure are applicable;

FIG. 35 is a block diagram illustrating another example of wirelessdevices to which various embodiments of the present disclosure areapplicable;

FIG. 36 is a block diagram illustrating a portable device applied tovarious embodiments of the present disclosure;

FIG. 37 is a block diagram illustrating a vehicle or an autonomousdriving vehicle, which is applied to various embodiments of the presentdisclosure; and

FIG. 38 is a block diagram illustrating a vehicle applied to variousembodiments of the present disclosure.

DETAILED DESCRIPTION

The various embodiments of the present disclosure described below arecombinations of elements and features of the various embodiments of thepresent disclosure in specific forms. The elements or features may beconsidered selective unless otherwise mentioned. Each element or featuremay be practiced without being combined with other elements or features.Further, various embodiments of the present disclosure may beconstructed by combining parts of the elements and/or features.Operation orders described in various embodiments of the presentdisclosure may be rearranged. Some constructions or elements of any oneembodiment may be included in another embodiment and may be replacedwith corresponding constructions or features of another embodiment.

In the description of the attached drawings, a detailed description ofknown procedures or steps of the various embodiments of the presentdisclosure will be avoided lest it should obscure the subject matter ofthe various embodiments of the present disclosure. In addition,procedures or steps that could be understood to those skilled in the artwill not be described either.

Throughout the specification, when a certain portion “includes” or“comprises” a certain component, this indicates that other componentsare not excluded and may be further included unless otherwise noted. Theterms “unit”, “-or/er” and “module” described in the specificationindicate a unit for processing at least one function or operation, whichmay be implemented by hardware, software or a combination thereof. Inaddition, the terms “a or an”, “one”, “the” etc. may include a singularrepresentation and a plural representation in the context of the variousembodiments of the present disclosure (more particularly, in the contextof the following claims) unless indicated otherwise in the specificationor unless context clearly indicates otherwise.

In the various embodiments of the present disclosure, a description ismainly made of a data transmission and reception relationship between abase station (BS) and a user equipment (UE). A BS refers to a terminalnode of a network, which directly communicates with a UE. A specificoperation described as being performed by the BS may be performed by anupper node of the BS.

Namely, it is apparent that, in a network comprised of a plurality ofnetwork nodes including a BS, various operations performed forcommunication with a UE may be performed by the BS, or network nodesother than the BS. The term ‘BS’ may be replaced with a fixed station, aNode B, an evolved Node B (eNode B or eNB), gNode B (gNB), an advancedbase station (ABS), an access point, etc.

In the various embodiments of the present disclosure, the term terminalmay be replaced with a UE, a mobile station (MS), a subscriber station(SS), a mobile subscriber station (MSS), a mobile terminal, an advancedmobile station (AMS), etc.

A transmission end is a fixed and/or mobile node that provides a dataservice or a voice service and a reception end is a fixed and/or mobilenode that receives a data service or a voice service. Therefore, a UEmay serve as a transmission end and a BS may serve as a reception end,on an uplink (UL). Likewise, the UE may serve as a reception end and theBS may serve as a transmission end, on a downlink (DL).

Various embodiments of the present disclosure may be supported bystandard specifications disclosed for at least one of wireless accesssystems including an institute of electrical and electronics engineers(IEEE) 802.xx system, a 3rd generation partnership project (3GPP)system, a 3GPP long term evolution (LTE) system, a 3GPP 5th generation(5G) new RAT (NR) system, and a 3GPP2 system. In particular, the variousembodiments of the present disclosure may be supported by the standardspecifications, 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS36.321, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212,3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.321, and 3GPP TS 38.331. Thatis, the steps or parts which are not described in the variousembodiments of the present disclosure may be described with reference tothe above standard specifications. Further, all terms used herein may bedescribed by the standard specifications.

Reference will now be made in detail to the various embodiments of thepresent disclosure with reference to the accompanying drawings. Thedetailed description, which will be given below with reference to theaccompanying drawings, is intended to explain exemplary embodiments ofthe present disclosure, rather than to show the only embodiments thatcan be implemented according to the disclosure.

The following detailed description includes specific terms in order toprovide a thorough understanding of the various embodiments of thepresent disclosure. However, it will be apparent to those skilled in theart that the specific terms may be replaced with other terms withoutdeparting the technical spirit and scope of the various embodiments ofthe present disclosure.

Hereinafter, 3GPP LTE/LTE-A systems and 3GPP NR system are explained,which are examples of wireless access systems.

The various embodiments of the present disclosure can be applied tovarious wireless access systems such as code division multiple access(CDMA), frequency division multiple access (FDMA), time divisionmultiple access (TDMA), orthogonal frequency division multiple access(OFDMA), Single carrier frequency division multiple access (SC-FDMA),and so on.

CDMA may be implemented as a radio technology such as universalterrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented asa radio technology such as global system for mobile communications(GSM)/general packet radio service (GPRS)/enhanced data rates for GSMevolution (EDGE). OFDMA may be implemented as a radio technology such asIEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA(E-UTRA), etc.

UTRA is a part of Universal Mobile Telecommunications System (UMTS).3GPP LTE is a part of evolved UMTS (E-UMTS) using E-UTRA, adopting OFDMAfor DL and SC-FDMA for UL. LTE-advanced (LTE-A) is an evolution of 3GPPLTE.

While the various embodiments of the present disclosure are described inthe context of 3GPP LTE/LTE-A systems and 3GPP NR system in order toclarify the technical features of the various embodiments of the presentdisclosure, the various embodiments of the present disclosure is alsoapplicable to an IEEE 802.16e/m system, etc.

1. Overview of 3GPP System

1.1. Physical Channels and General Signal Transmission

In a wireless access system, a UE receives information from a BS on a DLand transmits information to the BS on a UL. The information transmittedand received between the UE and the BS includes general data informationand various types of control information. There are many physicalchannels according to the types/usages of information transmitted andreceived between the BS and the UE.

FIG. 1 is a diagram illustrating physical channels and a signaltransmission method using the physical channels, which may be used invarious embodiments of the present disclosure.

When a UE is powered on or enters a new cell, the UE performs initialcell search (S11). The initial cell search involves acquisition ofsynchronization to a BS. Specifically, the UE synchronizes its timing tothe BS and acquires information such as a cell identifier (ID) byreceiving a primary synchronization channel (P-SCH) and a secondarysynchronization channel (S-SCH) from the BS.

Then the UE may acquire information broadcast in the cell by receiving aphysical broadcast channel (PBCH) from the BS.

During the initial cell search, the UE may monitor a DL channel state byreceiving a downlink reference signal (DL RS).

After the initial cell search, the UE may acquire more detailed systeminformation by receiving a physical downlink control channel (PDCCH) andreceiving on a physical downlink shared channel (PDSCH) based oninformation of the PDCCH (S12).

Subsequently, to complete connection to the BS, the UE may perform arandom access procedure with the BS (S13 to S16). In the random accessprocedure, the UE may transmit a preamble on a physical random accesschannel (PRACH) (S13) and may receive a PDCCH and a random accessresponse (RAR) for the preamble on a PDSCH associated with the PDCCH(S14). The UE may transmit a PUSCH by using scheduling information inthe RAR (S15), and perform a contention resolution procedure includingreception of a PDCCH signal and a PDSCH signal corresponding to thePDCCH signal (S16).

When the random access procedure is performed in two steps, steps S13and S15 may be performed in one operation for a UE transmission, andsteps S14 and S16 may be performed in one operation for a BStransmission.

After the above procedure, the UE may receive a PDCCH and/or a PDSCHfrom the BS (S17) and transmit a physical uplink shared channel (PUSCH)and/or a physical uplink control channel (PUCCH) to the BS (S18), in ageneral UL/DL signal transmission procedure.

Control information that the UE transmits to the BS is genericallycalled UCI. The UCI includes a hybrid automatic repeat and requestacknowledgement/negative acknowledgement (HARQ-ACK/NACK), a schedulingrequest (SR), a channel quality indicator (CQI), a precoding matrixindex (PMI), a rank indicator (RI), etc.

In general, UCI is transmitted periodically on a PUCCH. However, ifcontrol information and traffic data should be transmittedsimultaneously, the control information and traffic data may betransmitted on a PUSCH. In addition, the UCI may be transmittedaperiodically on the PUSCH, upon receipt of a request/command from anetwork.

1.2. Radio Frame Structures

FIG. 2 is a diagram illustrating a radio frame structure in an NR systemto which various embodiments of the present disclosure are applicable.

The NR system may support multiple numerologies. A numerology may bedefined by a subcarrier spacing (SCS) and a cyclic prefix (CP) overhead.Multiple SCSs may be derived by scaling a default SCS by an integer N(or μ). Further, even though it is assumed that a very small SCS is notused in a very high carrier frequency, a numerology to be used may beselected independently of the frequency band of a cell. Further, the NRsystem may support various frame structures according to multiplenumerologies.

Now, a description will be given of OFDM numerologies and framestructures which may be considered for the NR system. Multiple OFDMnumerologies supported by the NR system may be defined as listed inTable 1. For a bandwidth part (BWP), μ and a CP are obtained from RRCparameters provided by the BS.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] Cyclic prefix 0  15 Normal 1  30 Normal2  60 Normal, Extended 3 120 Normal 4 240 Normal

In NR, multiple numerologies (e.g., SCSs) are supported to support avariety of 5G services. For example, a wide area in cellular bands issupported for an SCS of 15 kHz, a dense-urban area, a lower latency, anda wider carrier bandwidth are supported for an SCS of 30 kHz/60 kHz, anda larger bandwidth than 24.25 GHz is supported for an SCS of 60 kHz ormore, to overcome phase noise.

An NR frequency band is defined by two types of frequency ranges, FR1and FR2. FR1 may be a sub-6 GHz range, and FR2 may be an above-6 GHzrange, that is, a millimeter wave (mmWave) band.

Table 2 below defines the NR frequency band, by way of example.

TABLE 2 Frequency range Corresponding Subcarrier designation frequencyrange Spacing FR1   410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

Regarding a frame structure in the NR system, the time-domain sizes ofvarious fields are represented as multiples of a basic time unit for NR,T_(c)=1/(Δf_(max)*N_(f)) where Δf_(max)=480*10³ Hz and a value N_(f)related to a fast Fourier transform (FFT) size or an inverse fastFourier transform (IFFT) size is given as N_(f)=4096. T_(c) and T_(s)which is an LTE-based time unit and sampling time, given as T_(s)=1/((15kHz)*2048) are placed in the following relationship: T_(s)/T_(c)=64. DLand UL transmissions are organized into (radio) frames each having aduration of T_(f)=(Δf_(max)*N_(f)/100)*T_(c)=10 ms. Each radio frameincludes 10 subframes each having a duration ofT_(sf)=(Δf_(max)*N_(f)/1000)*T_(c)=1 ms. There may exist one set offrames for UL and one set of frames for DL. For a numerology μ, slotsare numbered with n^(μ) _(s)∈{0, . . . , N^(slot,μ) _(subframe)−1} in anincreasing order in a subframe, and with n^(μ) _(s,f)∈{0, . . . ,N^(slot,μ) _(frame)−1} in an increasing order in a radio frame. One slotincludes N^(μ) _(symb) consecutive OFDM symbols, and N^(μ) _(symb)depends on a CP. The start of a slot n^(μ) _(s) in a subframe is alignedin time with the start of an OFDM symbol n^(μ) _(s)*N^(μ) _(symb) in thesame subframe.

Table 3 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe, for each SCS in a normal CPcase, and Table 4 lists the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe, for each SCS inan extended CP case.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame,μ) N_(slot) ^(subframe,μ) 014 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14  160  16

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame,μ) N_(slot) ^(subframe,μ) 212 40 4

In the above tables, N^(slot) _(symb) represents the number of symbolsin a slot N^(frame,μ) _(slot), represents the number of slots in aframe, and N^(subframe,μ) _(slot) represents the number of slots in asubframe.

In the NR system to which various embodiments of the present disclosureare applicable, different OFDM(A) numerologies (e.g., SCSs, CP lengths,and so on) may be configured for a plurality of cells which areaggregated for one UE. Accordingly, the (absolute time) period of a timeresource including the same number of symbols (e.g., a subframe (SF), aslot, or a TTI) (generically referred to as a time unit (TU), forconvenience) may be configured differently for the aggregated cells.

FIG. 2 illustrates an example with μ=2 (i.e., an SCS of 60 kHz), inwhich referring to Table 6, one subframe may include four slots. Onesubframe={1, 2, 4} slots in FIG. 7, which is exemplary, and the numberof slot(s) which may be included in one subframe is defined as listed inTable 3 or Table 4.

Further, a mini-slot may include 2, 4 or 7 symbols, fewer symbols than2, or more symbols than 7.

FIG. 3 is a diagram illustrating a slot structure in an NR system towhich various embodiments of the present disclosure are applicable.

Referring FIG. 3, one slot includes a plurality of symbols in the timedomain. For example, one slot includes 7 symbols in a normal CP case and6 symbols in an extended CP case.

A carrier includes a plurality of subcarriers in the frequency domain.An RB is defined by a plurality of (e.g., 12) consecutive subcarriers inthe frequency domain.

A BWP, which is defined by a plurality of consecutive (P)RBs in thefrequency domain, may correspond to one numerology (e.g., SCS, CPlength, and so on).

A carrier may include up to N (e.g., 5) BWPs. Data communication may beconducted in an activated BWP, and only one BWP may be activated for oneUE. In a resource grid, each element is referred to as an RE, to whichone complex symbol may be mapped.

FIG. 4 is a diagram illustrating a self-contained slot structure towhich various embodiments of the present disclosure are applicable.

The self-contained slot structure may refer to a slot structure in whichall of a DL control channel, DL/UL data, and a UL control channel may beincluded in one slot.

In FIG. 4, the hatched area (e.g., symbol index=0) indicates a DLcontrol region, and the black area (e.g., symbol index=13) indicates aUL control region. The remaining area (e.g., symbol index=1 to 12) maybe used for DL or UL data transmission.

Based on this structure, a BS and a UE may sequentially perform DLtransmission and UL transmission in one slot. That is, the BS and UE maytransmit and receive not only DL data but also a UL ACK/NACK for the DLdata in one slot. Consequently, this structure may reduce a timerequired until data retransmission when a data transmission erroroccurs, thereby minimizing the latency of a final data transmission.

In this self-contained slot structure, a predetermined length of timegap is required to allow the BS and the UE to switch from transmissionmode to reception mode and vice versa. To this end, in theself-contained slot structure, some OFDM symbols at the time ofswitching from DL to UL may be configured as a guard period (GP).

While the self-contained slot structure has been described above asincluding both of a DL control region and a UL control region, thecontrol regions may selectively be included in the self-contained slotstructure. In other words, the self-contained slot structure accordingto various embodiments of the present disclosure may cover a case ofincluding only the DL control region or the UL control region as well asa case of including both of the DL control region and the UL controlregion, as illustrated in FIG. 4.

Further, the sequence of the regions included in one slot may varyaccording to embodiments. For example, one slot may include the DLcontrol region, the DL data region, the UL control region, and the ULdata region in this order, or the UL control region, the UL data region,the DL control region, and the DL data region in this order.

A PDCCH may be transmitted in the DL control region, and a PDSCH may betransmitted in the DL data region. A PUCCH may be transmitted in the ULcontrol region, and a PUSCH may be transmitted in the UL data region.

1.3. Channel Structures

1.3.1. DL Channel Structures

The BS transmits related signals to the UE on DL channels as describedbelow, and the UE receives the related signals from the BS on the DLchannels.

1.3.1.1. Physical Downlink Shared Channel (PDSCH)

The PDSCH conveys DL data (e.g., DL-shared channel transport block(DL-SCH TB)) and uses a modulation scheme such as quadrature phase shiftkeying (QPSK), 16-ary quadrature amplitude modulation (16QAM), 64QAM, or256QAM. A TB is encoded into a codeword. The PDSCH may deliver up to twocodewords. Scrambling and modulation mapping are performed on a codewordbasis, and modulation symbols generated from each codeword are mapped toone or more layers (layer mapping). Each layer together with ademodulation reference signal (DMRS) is mapped to resources, generatedas an OFDM symbol signal, and transmitted through a correspondingantenna port.

1.3.1.2. Physical Downlink Control Channel (PDCCH)

The PDCCH may deliver downlink control information (DCI), for example,DL data scheduling information, UL data scheduling information, and soon. The PUCCH may deliver uplink control information (UCI), for example,an ACK/NACK information for DL data, channel state information (CSI), ascheduling request (SR), and so on.

The PDCCH carries DCI and is modulated in QPSK. One PDCCH includes 1, 2,4, 8, or 16 control channel elements (CCEs) according to an aggregationlevel (AL). One CCE includes 6 resource element groups (REGs). One REGis defined by one OFDM symbol by one (P)RB.

FIG. 5 is a diagram illustrating the structure of one REG to whichvarious embodiments of the present disclosure are applicable.

In FIG. 5, D represents an RE to which DCI is mapped, and R representsan RE to which a DMRS is mapped. The DMRS is mapped to REs #1, #5, and#9 along the frequency axis in one symbol.

The PDCCH is transmitted in a control resource set (CORESET). A CORESETis defined as a set of REGs having a given numerology (e.g., SCS, CPlength, and so on). A plurality of CORESETs for one UE may overlap witheach other in the time/frequency domain. A CORESET may be configured bysystem information (e.g., a master information block (MIB)) or byUE-specific higher layer (RRC) signaling. Specifically, the number ofRBs and the number of symbols (up to 3 symbols) included in a CORESETmay be configured by higher-layer signaling.

For each CORESET, a precoder granularity in the frequency domain is setto one of the followings by higher-layer signaling:

-   -   sameAsREG-bundle: It equals to an REG bundle size in the        frequency domain.    -   allContiguousRBs: It equals to the number of contiguous RBs in        the frequency domain within the CORESET.

The REGs of the CORESET are numbered in a time-first mapping manner.That is, the REGs are sequentially numbered in an increasing order,starting with 0 for the first OFDM symbol of the lowest-numbered RB inthe CORESET.

CCE-to-REG mapping for the CORESET may be an interleaved type or anon-interleaved type.

FIGS. 6A and 6B are diagrams illustrating exemplary CCE-to-REG mappingtypes according to various embodiments of the present disclosure.

FIG. 6A is a diagram illustrating exemplary non-interleaved CCE-to-REGmapping according to various embodiments of the present disclosure.

-   -   Non-interleaved CCE-to-REG mapping (or localized CCE-to-REG        mapping): 6 REGs for a given CCE are grouped into one REG        bundle, and all of the REGs for the given CCE are contiguous.        One REG bundle corresponds to one CCE.

FIG. 6B is a diagram illustrating exemplary interleaved CCE-to-REGmapping.

-   -   Interleaved CCE-to-REG mapping (or distributed CCE-to-REG        mapping): 2, 3 or 6 REGs for a given CCE are grouped into one        REG bundle, and the REG bundle is interleaved in the CORESET. In        a CORESET including one or two OFDM symbols, an REG bundle        includes 2 or 6 REGs, and in a CORESET including three OFDM        symbols, an REG bundle includes 3 or 6 REGs. An REG bundle size        is configured on a CORESET basis.

FIG. 7 illustrates an exemplary block interleaver according to variousembodiments of the present disclosure.

For the above interleaving operation, the number A of rows in a (block)interleaver is set to one of 2, 3, and 6. If the number of interleavingunits for a given CORESET is P, the number of columns in the blockinterleaver is P/A. In the block interleaver, a write operation isperformed in a row-first direction, and a read operation is performed ina column-first direction, as illustrated in FIG. C4. Cyclic shift (CS)of an interleaving unit is applied based on an ID which is configurableindependently of a configurable ID for the DMRS.

The UE acquires DCI delivered on a PDCCH by decoding (so-called blinddecoding) a set of PDCCH candidates. A set of PDCCH candidates decodedby a UE are defined as a PDCCH search space set. A search space set maybe a common search space (CSS) or a UE-specific search space (USS). TheUE may acquire DCI by monitoring PDCCH candidates in one or more searchspace sets configured by an MIB or higher-layer signaling. Each CORESETconfiguration is associated with one or more search space sets, and eachsearch space set is associated with one CORESET configuration. Onesearch space set is determined based on the following parameters.

-   -   controlResourceSetId: A set of control resources related to the        search space set.    -   monitoringSlotPeriodiciyAndoffset: A PDCCH monitoring        periodicity (in slots) and a PDCCH monitoring offset (in slots).    -   monitoringSymbolsWithinSlot: A PDCCH monitoring pattern (e.g.,        the first symbol(s) in the CORESET) in a PDCCH monitoring slot.    -   nrofCandidates: The number of PDCCH candidates for each AL={1,        2, 4, 8, 16} (one of 0, 1, 2, 3, 4, 5, 6, and 8).

Table 5 lists exemplary features of the respective search space types.

TABLE 5 Search Type Space RNTI Use Case Type0-PDCCH Common SI-RNTI on aprimary cell SIB Decoding Type0A-PDCCH Common SI-RNTI on a primary cellSIB Decoding Type 1-PDCCH Common RA-RNTI or TC-RNTI on a primary Msg2 ,Msg4 cell decoding in RACH Type2-PDCCH Common P-RNTI on a primary cellPaging Decoding Type3-PDCCH Common INT-RNTI , SFI-RNTI , TPC-PUSCH- RNTI, TPC-PUCCH-RNTI , TPC-SRS- RNTI, C-RNTI , MCS-C-RNTI , or CS- RNTI ( s) UE C-RNTI , or MCS-C-RNTI , or CS- User specific Specific RNTI(s)PDSCH decoding

Table 6 lists exemplary DCI formats transmitted on the PDCCH.

TABLE 6 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRD(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used to schedule a TB-based (or TB-level) PUSCH,and DCI format 0_1 may be used to schedule a TB-based (or TB-level)PUSCH or a code block group (CBG)-based (or CBG-level) PUSCH. DCI format1_0 may be used to schedule a TB-based (or TB-level) PDSCH, and DCIformat 1_1 may be used to schedule a TB-based (or TB-level) PDSCH or aCBG-based (or CBG-level) PDSCH. DCI format 2_0 is used to deliverdynamic slot format information (e.g., a dynamic slot format indicator(SFI)) to the UE, and DCI format 2_1 is used to deliver DL preemptioninformation to the UE. DCI format 2_0 and/or DCI format 2_1 may bedelivered to the UEs of a group on a group common PDCCH (GC-PDCCH) whichis a PDCCH directed to a group of UEs.

1.3.2. UL Channel Structures

The UE transmits related signals on later-described UL channels to theBS, and the BS receives the related signals on the UL channels from theUE.

1.3.2.1. Physical Uplink Shared Channel (PUSCH)

The PUSCH delivers UL data (e.g., a UL-shared channel transport block(UL-SCH TB)) and/or UCI, in cyclic prefix-orthogonal frequency divisionmultiplexing (CP-OFDM) waveforms or discrete Fouriertransform-spread-orthogonal division multiplexing (DFT-s-OFDM)waveforms. If the PUSCH is transmitted in DFT-s-OFDM waveforms, the UEtransmits the PUSCH by applying transform precoding. For example, iftransform precoding is impossible (e.g., transform precoding isdisabled), the UE may transmit the PUSCH in CP-OFDM waveforms, and iftransform precoding is possible (e.g., transform precoding is enabled),the UE may transmit the PUSCH in CP-OFDM waveforms or DFT-s-OFDMwaveforms. The PUSCH transmission may be scheduled dynamically by a ULgrant in DCI or semi-statically by higher-layer signaling (e.g., RRCsignaling) (and/or layer 1 (L1) signaling (e.g., a PDCCH)) (a configuredgrant). The PUSCH transmission may be performed in a codebook-based ornon-codebook-based manner.

1.3.2.2. Physical Uplink Control Channel (PUCCH)

The PUCCH delivers UCI, an HARQ-ACK, and/or an SR and is classified as ashort PUCCH or a long PUCCH according to the transmission duration ofthe PUCCH. Table 7 lists exemplary PUCCH formats.

TABLE 7 PUCCH Length in OFDM Number of format symbols NsymbPUCCH bitsUsage Etc 0 1-2 ≤2 HARQ, SR Sequence selection 1  4-14 ≤2 HARQ, [SR]Sequence modulation 2 1-2 >2 HARQ, CSI, [SR] CP-OFDM 3  4-14 >2 HARQ,CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4  4-14 >2 HARQ, CSI, [SR]DFT-s-OFDM (Pre DFT OCC)

PUCCH format 0 conveys UCI of up to 2 bits and is mapped in asequence-based manner, for transmission. Specifically, the UE transmitsspecific UCI to the BS by transmitting one of a plurality of sequenceson a PUCCH of PUCCH format 0. Only when the UE transmits a positive SR,the UE transmits the PUCCH of PUCCH format 0 in a PUCCH resource for acorresponding SR configuration.

PUCCH format 1 conveys UCI of up to 2 bits and modulation symbols of theUCI are spread with an OCC (which is configured differently whetherfrequency hopping is performed) in the time domain. The DMRS istransmitted in a symbol in which a modulation symbol is not transmitted(i.e., transmitted in time division multiplexing (TDM)).

PUCCH format 2 conveys UCI of more than 2 bits and modulation symbols ofthe DCI are transmitted in frequency division multiplexing (FDM) withthe DMRS. The DMRS is located in symbols #1, #4, #7, and #10 of a givenRB with a density of ⅓. A pseudo noise (PN) sequence is used for a DMRSsequence. For 1-symbol PUCCH format 2, frequency hopping may beactivated.

PUCCH format 3 does not support UE multiplexing in the same PRBS, andconveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 do not include an OCC. Modulation symbols are transmittedin TDM with the DMRS.

PUCCH format 4 supports multiplexing of up to 4 UEs in the same PRBS,and conveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 includes an OCC. Modulation symbols are transmitted inTDM with the DMRS.

1.4. Analog Beamforming

In a millimeter wave (mmW) system, since a wavelength is short, aplurality of antenna elements can be installed in the same area. Thatis, considering that the wavelength at 30 GHz band is 1 cm, a total of100 antenna elements can be installed in a 5*5 cm panel at intervals of0.5 lambda (wavelength) in the case of a 2-dimensional array. Therefore,in the mmW system, it is possible to improve the coverage or throughputby increasing the beamforming (BF) gain using multiple antenna elements.

In this case, each antenna element can include a transceiver unit (TXRU)to enable adjustment of transmit power and phase per antenna element. Bydoing so, each antenna element can perform independent beamforming perfrequency resource.

However, installing TXRUs in all of the about 100 antenna elements isless feasible in terms of cost. Therefore, a method of mapping aplurality of antenna elements to one TXRU and adjusting the direction ofa beam using an analog phase shifter has been considered. However, thismethod is disadvantageous in that frequency selective beamforming isimpossible because only one beam direction is generated over the fullband.

To solve this problem, as an intermediate form of digital BF and analogBF, hybrid BF with B TXRUs that are fewer than Q antenna elements can beconsidered. In the case of the hybrid BF, the number of beam directionsthat can be transmitted at the same time is limited to B or less, whichdepends on how B TXRUs and Q antenna elements are connected.

FIGS. 8 and 9 are diagrams illustrating representative methods forconnecting TXRUs to antenna elements. Here, the TXRU virtualizationmodel represents the relationship between TXRU output signals andantenna element output signals.

FIG. 8 shows a method for connecting TXRUs to sub-arrays. In FIG. 8, oneantenna element is connected to one TXRU.

Meanwhile, FIG. 9 shows a method for connecting all TXRUs to all antennaelements. In FIG. 9, all antenna elements are connected to all TXRUs. Inthis case, separate addition units are required to connect all antennaelements to all TXRUs as shown in FIG. 9.

In FIGS. 8 and 9, W indicates a phase vector weighted by an analog phaseshifter. That is, W is a major parameter determining the direction ofthe analog beamforming. In this case, the mapping relationship betweenchannel state information-reference signal (CSI-RS) antenna ports andTXRUs may be 1:1 or 1-to-many.

The configuration shown in FIG. 8 has a disadvantage in that it isdifficult to achieve beamforming focusing but has an advantage in thatall antennas can be configured at low cost.

On the contrary, the configuration shown in FIG. 9 is advantageous inthat beamforming focusing can be easily achieved. However, since allantenna elements are connected to the TXRU, it has a disadvantage ofhigh cost.

When a plurality of antennas is used in the NR system to which thepresent disclosure is applicable, a hybrid beamforming (BF) scheme inwhich digital BF and analog BF are combined may be applied. In thiscase, analog BF (or radio frequency (RF) BF) means an operation ofperforming precoding (or combining) at an RF stage. In hybrid BF, eachof a baseband stage and the RF stage perform precoding (or combining)and, therefore, performance approximating to digital BF can be achievedwhile reducing the number of RF chains and the number of adigital-to-analog (D/A) (or analog-to-digital (A/D) converters.

For convenience of description, a hybrid BF structure may be representedby N TXRUs and M physical antennas. In this case, digital BF for L datalayers to be transmitted by a transmission end may be represented by anN-by-L matrix. N converted digital signals obtained thereafter areconverted into analog signals via the TXRUs and then subjected to analogBF, which is represented by an M-by-N matrix.

FIG. 10 is a diagram schematically illustrating an exemplary hybrid BFstructure from the perspective of TXRUs and physical antennas accordingto the present disclosure. In FIG. 10, the number of digital beams is Land the number analog beams is N.

Additionally, in the NR system to which the present disclosure isapplicable, an BS designs analog BF to be changed in units of symbols toprovide more efficient BF support to a UE located in a specific area.Furthermore, as illustrated in FIG. 7, when N specific TXRUs and M RFantennas are defined as one antenna panel, the NR system according tothe present disclosure considers introducing a plurality of antennapanels to which independent hybrid BF is applicable.

In the case in which the BS utilizes a plurality of analog beams asdescribed above, the analog beams advantageous for signal reception maydiffer according to a UE. Therefore, in the NR system to which thepresent disclosure is applicable, a beam sweeping operation is beingconsidered in which the BS transmits signals (at least synchronizationsignals, system information, paging, and the like) by applying differentanalog beams in a specific subframe or slot on a symbol-by-symbol basisso that all UEs may have reception opportunities.

FIG. 11 is a simplified diagram illustrating a beam sweeping operationfor a synchronization signal and system information in a DL transmissionprocedure according to various embodiments of the present disclosure.

In FIG. 11, a physical resource (or physical channel) in which thesystem information of the NR system to which various embodiments of thepresent disclosure are applicable is transmitted in a broadcastingmanner is referred to as an xPBCH. Analog beams belonging to differentantenna panels may be transmitted simultaneously in one symbol.

As illustrated in FIG. 11, in order to measure a channel for each analogbeam in the NR system to which various embodiments of the presentdisclosure are applicable, a beam RS (BRS), which is a reference signal(RS) transmitted by applying a single analog beam (corresponding to aspecific antenna panel), may be introduced. The BRS may be defined for aplurality of antenna ports, and each antenna port of the BRS maycorrespond to a single analog beam. Unlike the BRS, a synchronizationsignal or the xPBCH may be transmitted by applying all analog beams ofan analog beam group such that any UE may receive the signalsuccessfully.

1.5. Cell Search

FIG. 12 is a diagram illustrating the structure of a synchronizationsignal block (SSB) to which various embodiments of the presentdisclosure are applicable.

A UE may perform cell search, system information acquisition, beamalignment for initial access, DL measurement, and so on based on an SSB.The term SSB is interchangeably used with synchronizationsignal/physical broadcast channel (SS/PBCH) block.

Referring to FIG. 12, the SSB to which various embodiments of thepresent disclosure are applicable may include 20 RBs in four consecutiveOFDM symbols. Further, the SSB may include a PSS, an SSS, and a PBCH,and the UE may perform cell search, system information acquisition, beamalignment for initial access, DL measurement, and so on based on theSSB.

Each of the PSS and the SSS includes one OFDM symbol by 127 subcarriers,and the PBCH includes three OFDM symbols by 576 subcarriers. Polarcoding and QPSK are applied to the PBCH. The PBCH includes data REs andDMRS REs in every OFDM symbol. There are three DMRS REs per RB, withthree data REs between every two adjacent DMRS REs.

Further, the SSB may be transmitted in a frequency band other than thecenter of the frequency band used by the network.

For this purpose, a synchronization raster being candidate frequencypositions at which the UE should detect the SSB is defined in the NRsystem to which various embodiments of the present disclosure areapplicable. The synchronization raster may be distinguished from achannel raster.

In the absence of explicit signaling of the position of the SSB, thesynchronization raster may indicate available frequency positions forthe SSB, at which the UE may acquire system information.

The synchronization raster may be determined based on a globalsynchronization channel number (GSCN). The GSCN may be transmitted byRRC signaling (e.g., an MIB, a system information block (SIB), remainingminimum system information (RMSI), other system information (OSI), orthe like).

The synchronization raster is defined to be longer along the frequencyaxis than the channel raster and characterized by a smaller number ofblind detections than the channel raster, in consideration of thecomplexity of initial synchronization and a detection speed.

Cell search refers to a procedure in which the UE acquirestime/frequency synchronization of a cell and detects a cell ID (e.g.,physical layer cell ID (PCID)) of the cell. The PSS may be used todetect a cell ID within a cell ID group, and the SSS may be used todetect the cell ID group. The PBCH may be used in detecting an SSB(time) index and a half-frame.

The cell search procedure of the UE may be summarized as described inTable 8 below.

TABLE 8 Type of Signals Operations 1^(st) PSS * SS/PBCH block (SSB)symbol timing step acquisition * Cell ID detection within a cell IDgroup (3 hypothesis) 2^(nd) SSS * Cell ID group detection (336hypothesis) Step 3^(rd) PBCH DMRS * SSB index and Half frame (HF) indexStep (Slot and frame boundary detection) 4^(th) PBCH * Time information(80 ms, System Frame Step Number (SFN), SSB index, 14F) * RemainingMinimum System Information (RMSI) Control resource set (CORESET)/Searchspace configuration 5^(th) PDCCE and * Cell access information StepPDSCH * RACH configuration

There are 336 cell ID groups each including three cell IDs. There are1008 cell IDs in total. Information about a cell ID group to which thecell ID of a cell belongs may be provided/obtained through the SSS ofthe cell, and information about the cell ID among 336 cells in the cellID may be provided/obtained through the PSS.

FIG. 13 is a diagram illustrating an exemplary SSB transmission methodto which various embodiments of the present disclosure are applicable.

Referring to FIG. 13, the SSB is periodically transmitted according toan SSB periodicity. A default SSB periodicity assumed by the UE duringinitial cell search is defined as 20 ms. After the cell access, the SSBperiodicity may be set to one of {5 ms, 10 ms, 20 ms, 40 ms, 80 ms, 160ms} by the network (e.g., the BS). An SSB burst set is configured at thebeginning of an SSB period. The SSB burst set may be configured with a5-ms time window (i.e., half-frame), and an SSB may be repeatedlytransmitted up to L times within the SS burst set. The maximum number oftransmissions of the SSB, L may be given according to the frequency bandof a carrier as follows. One slot includes up to two SSBs.

-   -   For frequency range up to 3 GHz, L=4    -   For frequency range from 3 GHz to 6 GHz, L=8    -   For frequency range from 6 GHz to 52.6 GHz, L=64

The time position of an SSB candidate in the SS burst set may be definedaccording to an SCS as follows. The time positions of SSB candidates areindexed as (SSB indexes) 0 to L−1 in time order within the SSB burst set(i.e., half-frame).

-   -   Case A: 15-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {2, 8}+14*n where n=0, 1 for a        carrier frequency equal to or lower than 3 GHz, and n=0, 1, 2, 3        for a carrier frequency of 3 GHz to 6 GHz.    -   Case B: 30-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {4, 8, 16, 20}+28*n where n=0 for a        carrier frequency equal to or lower than 3 GHz, and n=0, 1 for a        carrier frequency of 3 GHz to 6 GHz.    -   Case C: 30-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {2, 8}+14*n where n=0, 1 for a        carrier frequency equal to or lower than 3 GHz, and n=0, 1, 2, 3        for a carrier frequency of 3 GHz to 6 GHz.    -   Case D: 120-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {4, 8, 16, 20}+28*n where n=0, 1, 2,        3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 for a carrier        frequency above 6 GHz.    -   Case E: 240-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {8, 12, 16, 20, 32, 36, 40, 44}+56*n        where n=0, 1, 2, 3, 5, 6, 7, 8 for a carrier frequency above 6        GHz.

1.6. Synchronization Procedure

The UE may acquire synchronization by receiving the above-described SSBfrom the BS. The synchronization procedure largely includes cell IDdetection and timing detection. The cell ID detection may includePSS-based cell ID detection and SSS-based cell ID detection. The timingdetection may include PBCH DMRS-based timing detection and PBCHcontent-based (e.g., MIB-based) timing detection.

First, the UE may acquire timing synchronization and the physical cellID of a detected cell by detecting a PSS and an SSS. More specifically,the UE may acquire the symbol timing of the SS block and detect a cellID within a cell ID group, by PSS detection. Subsequently, the UEdetects the cell ID group by SSS detection.

Further, the UE may detect the time index (e.g., slot boundary) of theSS block by the DMRS of the PBCH. The UE may then acquire half-frameboundary information and system frame number (SFN) information from anMIB included in the PBCH.

The PBCH may indicate that a related (or corresponding) RMSI PDCCH/PDSCHis transmitted in the same band as or a different band from that of theSS/PBCH block. Accordingly, the UE may then receive RMSI (e.g., systeminformation other than the MIB) in a frequency band indicated by thePBCH or a frequency band carrying the PBCH, after decoding the PBCH.

In relation to the operation, the UE may acquire system information.

The MIB includes information/parameters required for monitoring a PDCCHthat schedules a PDSCH carrying SystemInformationBlock1 (SIB1), and istransmitted to the UE on the PBCH in the SS/PBCH block by the BS.

The UE may check whether there is a CORESET for a TypeO-PDCCH commonsearch space, based on the MIB. The TypeO-PDCCH common search space is akind of PDCCH search space and used to transmit a PDCCH that schedules asystem information (SI) message.

In the presence of a TypeO-PDCCH common search space, the UE maydetermine (i) a plurality of contiguous RBs included in the CORESET andone or more consecutive symbols and (ii) a PDCCH occasion (e.g., atime-domain position for PDCCH reception), based on information (e.g.,pdcch-ConfigSIB1) included in the MIB.

In the absence of a TypeO-PDCCH common search space, pdcch-ConfigSIB1provides information about a frequency position at which the SSB/SIB1exists and a frequency range in which the SSB/SIB1 does not exist.

SIB1 includes information about the availability and scheduling of theother SIBs (hereinafter, referred to as SIBx where x is an integer equalto or larger than 2). For example, SIB1 may indicate whether SIBx isperiodically broadcast or provided in an on-demand manner (or uponrequest of the UE). When SIBx is provided in the on-demand manner, SIB1may include information required for an SI request of the UE. SIB1 istransmitted on a PDSCH. A PDCCH that schedules SIB1 is transmitted in aTypeO-PDCCH common search space, and SIB1 is transmitted on a PDSCHindicated by the PDCCH.

1.7. Quasi Co-Located or Quasi Co-Location (QCL)

The UE may receive a list of up to M candidate transmissionconfiguration indication (TCI)-State configurations to decode a PDSCHaccording to a detected PDCCH carrying DCI intended for the UE and agiven cell. M depends on a UE capability.

Each TCI-State includes a parameter for establishing a QCL relationshipbetween one or two DL RSs and a PDSCH DMRS port. The QCL relationship isestablished with an RRC parameter qcl-Type1 for a first DL RS and an RRCparameter qcl-Type2 for a second DL RS (if configured).

The QCL type of each DL RS is given by a parameter ‘gel-Type’ includedin QCL-Info, and may have one of the following values.

-   -   ‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay,        delay spread}    -   ‘QCL-TypeB’: {Doppler shift, Doppler spread}    -   ‘QCL-TypeC’: {Doppler shift, average delay}    -   ‘QCL-TypeD’: {Spatial Rx parameter}

For example, when a target antenna port is for a specific non-zero power(NZP) CSI-RS, corresponding NZP CSI-RS antenna ports may beindicated/configured as QCLed with a specific TRS from the perspectiveof QCL-Type A and with a specific SSB from the perspective of QCL-TypeD. Upon receipt of this indication/configuration, the UE may receive theNZP CSI-RS using a Doppler value and a delay value which are measured ina QCL-TypeA TRS, and apply a reception (Rx) beam used to receive aQCL-Type D SSB for reception of the NZP CSI-RS.

1.8. Unlicensed Band/Shared Spectrum System

FIGS. 14A and 14B are diagrams illustrating an exemplary wirelesscommunication system supporting an unlicensed band to which variousembodiments of the present disclosure are applicable.

In the following description, a cell operating in a licensed band(hereinafter, referred to as L-band) is defined as an L-cell, and acarrier of the L-cell is defined as a (DL/UL) LCC. In addition, a celloperating in an unlicensed band (hereinafter, referred to as a U-band)is defined as a U-cell, and a carrier of the U-cell is defined as a(DL/UL) UCC. The carrier/carrier-frequency of a cell may refer to theoperating frequency (e.g., center frequency) of the cell. A cell/carrier(e.g., component carrier (CC)) is collectively referred to as a cell.

As illustrated in FIG. 14A, when the UE and the BS transmit and receivesignals in carrier-aggregated LCC and UCC, the LCC may be configured asa primary CC (PCC) and the UCC may be configured as a secondary CC(SCC).

As illustrated in FIG. 14B, the UE and the BS may transmit and receivesignals in one UCC or a plurality of carrier-aggregated LCC and UCC.That is, the UE and the BS may transmit and receive signals only in theUCC(s) without the LCC. An operation of transmitting and receiving asignal in an unlicensed band as described in various embodiments of thepresent disclosure may be performed based on all the deploymentscenarios described above (unless otherwise stated).

1.8.1. Radio Frame Structure for Unlicensed Band

LTE frame structure type 3 or an NR frame structure may be used foroperation in an unlicensed band. The configuration of OFDM symbolsoccupied for a UL/DL signal transmission in the frame structure for theunlicensed band may be configured by the BS. Herein, an OFDM symbol maybe replaced with an SC-FDM(A) symbol.

For a DL signal transmission in the unlicensed band, the BS may indicatethe configuration of OFDM symbols used in subframe #n to the UE bysignaling. In the following description, a subframe may be replaced witha slot or a TU.

Specifically, in the wireless communication system supporting theunlicensed band, the UE may assume (or identify) the configuration ofOFDM symbols occupied in subframe #n by a specific field (e.g., aSubframe configuration for LAA field) in DCI received in subframe #n−1or subframe #n from the BS.

Table 9 illustrates an exemplary method of indicating the configurationof OFDM symbols used for transmission of a DL physical channel and/orphysical signal in a current and/or next subframe by the Subframeconfiguration for LAA field in the wireless communication system.

TABLE 9 Value of Configuration of occupied OFDM ‘Subframe configurationfor LAA’ symbols field in current subframe (current subframe, nextsubframe) 0000 (—, 14) 0001 (—, 12) 0010 (—, 11) 0011 (—, 10) 0100 (—,9) 0101 (—, 6) 0110 (—, 3) 0111 (14, *) 1000 (12, —) 1001 (11, —) 1010(10, —) 1011 (9, —) 1100 (6, —) 1101 (3, —) 1110 reserved 1111 reservedNOTE: (—, Y) means UE may assume the first Y symbols are occupied innext subframe and other symbols in the next subframe are not occupied.(X, —) means UE may assume the first X symbols are occupied in currentsubframe and other symbols in the current subframe are not occupied. (X,*) means UE may assume the first X symbols are occupied in currentsubframe, and at least the first OFDM symbol of the next subframe is notoccupied.

For a UL signal transmission in the unlicensed band, the BS may transmitinformation about a UL transmission period to the UE by signaling.

Specifically, in an LTE system supporting an unlicensed band, the UE mayacquire ‘UL duration’ and ‘UL offset’ information for subframe #n from a‘UL duration and offset’ field in detected DCI.

Table 10 illustrates an exemplary method of indicating a UL offset andUL duration configuration by the UL duration and offset field in thewireless communication system.

TABLE 10 Value of UL offset, l UL duration, d ‘UL duration and offset’field (in subframes) (in subframes) 00000 Not configured Not configured00001 1 1 00010 1 2 00011 1 3 00100 1 4 00101 1 5 00110 1 6 00111 2 101000 2 2 01001 2 3 01010 2 4 01011 2 5 01100 2 6 01101 3 1 01110 3 201111 3 3 10000 3 4 10001 3 5 10010 3 6 10011 4 1 10100 4 2 10101 4 310110 4 4 10111 4 5 11000 4 6 11001 6 1 11010 6 2 11011 6 3 11100 6 411101 6 5 11110 6 6 11111 reserved reserved

1.8.2. Overview of Channel Access Procedures

Unless otherwise noted, the definitions below are applicable toterminologies used in the following description of various embodimentsof the present disclosure.

-   -   A channel refers to a carrier or a part of a carrier including a        set of consecutive RBs in which a channel access procedure is        performed in a shared spectrum.    -   A channel access procedure may be a procedure based on sensing        that evaluates the availability of a channel for performing a        transmission. A basic unit for sensing is a sensing slot with a        duration of Tsl=9 us. The sensing slot duration may be        considered to be idle if the BS or the UE senses the channel        during the sensing slot duration, and determines that detected        power for at least 4 us within the sensing slot duration is less        than an energy detection threshold XThresh. Otherwise, the        sensing slot duration Tsl may be considered to be busy.    -   Channel occupancy refers to transmission(s) on channel(s) from        the BS/UE after performing a corresponding channel access        procedure in this subclause.    -   A channel occupancy time refers to the total time during which        the BS/UE and any BS/UE sharing channel occupancy performs        transmission(s) on a channel after the BS/UE performs the        corresponding channel access procedure described in this        subclause. For determining a channel occupancy time, if a        transmission gap is less than or equal to 25 us, the gap        duration may be counted in the channel occupancy time. The        channel occupancy time may be shared for transmission between        the BS and corresponding UE(s).

1.8.3. Downlink Channel Access Procedure

For a DL signal transmission in an unlicensed band, the BS may perform aDL channel access procedure (CAP) for the unlicensed band as follows.

1.8.3.1. Type 1 DL Channel Access Procedures

This subclause describes CAPs to be performed by the BS, in which a timeduration spanned by sensing slots sensed to be idle before DLtransmission(s) is random. This subclause is applicable to the followingtransmissions:

-   -   Transmission(s) initiated by a BS including a        PDSCH/PDCCH/EPDCCH, or    -   Transmission(s) initiated by a BS including a unicast PDSCH with        user plane data, or a unicast PDSCH with user plane data and a        unicast PDCCH scheduling user plane data, or    -   Transmission(s) initiated by a BS with only a discovery burst or        with a discovery burst multiplexed with non-unicast information,        where the duration of the transmission(s) is larger than 1 ms or        the transmission causes the discovery burst duty cycle to exceed        1/20.

FIG. 15 is a diagram illustrating a DL CAP for transmission in anunlicensed band, to which various embodiments of the present disclosureare applicable.

A Type 1 DL CAP for transmission in an unlicensed band, to which variousembodiments of the present disclosure are applicable may be summarizedas follows.

For a DL transmission, a transmission node (e.g., a BS) may initiate aCAP (2010).

The BS may randomly select a backoff counter N within a contentionwindow (CW) according to step 1. N is set to an initial value N_(init)(2020). N_(init) is a random value selected between 0 and CW_(p).

Subsequently, when the backoff counter value N is 0 according to step 4(2030; Y), the BS terminates the CAP (2032). The BS may then perform atransmission (Tx) burst transmission (2034). On the contrary, when thebackoff counter value N is not 0 (2030; N), the BS decrements thebackoff counter value by 1 according to step 2 (2040).

Subsequently, the BS checks whether the channel is idle (2050). If thechannel is idle (2050; Y), the BS determines whether the backoff countervalue is 0 (2030).

On the contrary, when the channel is not idle, that is, the channel isbusy in operation 2050 (2050; N), the BS determines whether the channelis idle during a longer defer duration Td (25 usec or longer) than asensing slot duration (e.g., 9 usec) (2060). If the channel is idleduring the defer duration (2070; Y), the BS may resume the CAP.

For example, when the backoff counter value N_(init) is 10 and thechannel is determined to be idle after the backoff counter value isdecremented to 5, the BS senses the channel during the defer durationand determines whether the channel is idle. If the channel is idleduring the defer duration, the BS may resume the CAP from the backoffcounter value 5 (or from the backoff counter value 4 obtained bydecrementing the backoff counter value 5 by 1), instead of setting thebackoff counter value N_(init).

On the other hand, when the channel is busy during the defer duration(2070; N), the BS determines again whether the channel is idle during anew defer duration by performing step 2060 again.

If the BS has not performed a transmission after step 4 in the aboveprocedure, the BS may perform the transmission on the channel, if thefollowing condition is satisfied:

If the BS is ready to transmit and the channel is sensed to be idleduring at least a sensing slot duration T_(sl), and if the channel hasbeen sensed to be idle during all the sensing slot durations of a deferduration T_(d) immediately before this transmission.

On the contrary, if the channel has not been sensed to be idle duringthe sensing slot duration T_(sl) when the BS first senses the channelafter it is ready to transmit or if the channel has not been sensed tobe idle during any of the sensing slot durations of the defer durationT_(d) immediately before this intended transmission, the BS proceeds tostep 1 after sensing the channel to be idle during the sensing slotdurations of the defer duration T_(sl).

The defer duration T_(d) includes a duration T_(f)(=16 us) immediatelyfollowed by m_(p) consecutive sensing slot durations. Each sensing slotduration Tis is 9 us and the duration T_(f) includes an idle sensingslot duration Tis at the start of the duration T_(f).

Table 11 illustrates that m_(p), a minimum CW, a maximum CW, a maximumchannel occupancy time (MCOT), and an allowed CW size applied to a CAPvary according to a channel access priority class.

TABLE 11 Channel Access Priority Class (p) m_(p) CW_(min,p) CW_(max,p)T_(mcot,p) allowed CW_(p) sizes 1 1 3 7 2 ms {3,7} 2 1 7 15 3 ms {7, 15}3 3 15 63 8 or 10 ms {15, 31, 63} 4 7 15 1023 8 or 10 ms {15, 31, 63,127, 255, 511, 1023}

1.8.3.2. Type 2A DL Channel Access Procedure

The BS may perform a DL transmission immediately after sensing acorresponding channel to be idle during at least a sensing durationT_(short dl) (=25 us). T_(short dl) at includes a duration T_(f) (=16us) following one sensing slot duration. T_(f) includes a sensing slotat the start of T_(f). If two sensing slots within T_(short dl) at aresensed to be idle, the channel is considered to be idle forT_(short dl).

1.8.4. Channel Access Procedure for Transmission(s) on Multiple Channels

The BS may access multiple channels on which a transmission is performedin one of the following Type A and Type B procedures.

1.8.4.1. Type A Multi-Carrier Access Procedures

According to the procedure described in this subclause, the BS performschannel access on each channel c_(i)∈C where C is a set of channels thatthe BS intends to transmit, =0, 1, . . . q−1, and q is the number ofchannels to be transmitted by the BS.

A counter N considered in a CAP is determined for each channel c_(i),and in this case, the counter for each channel is represented as N_(c)_(i) .

1.8.4.1.1. Type A1 Multi-Carrier Access Procedure

The counter N considered in the CAP is determined independently for eachchannel c_(i), and the counter for each channel is represented as N_(c)_(i) .

In the case where the BS ceases a transmission on one channel c_(j)∈C,if the absence of any other technology sharing the channel may beguaranteed on a long term basis (e.g., by level of regulation), the BSmay resume N_(c) _(i) reduction, when an idle slot is detected afterwaiting for a duration of 4. T_(sl) or reinitializing N_(c) _(i) , foreach channel c_(i) (where c_(i) is different from c_(j)(c_(i)·c_(j))).

1.8.4.1.1.2. Type A2 Multi-Carrier Access Procedure

The counter N for each channel c_(j)∈C may be determined according tothe afore-described subclause 1.8.3., and is denoted by N_(c) _(j) .Here, c_(j) may mean a channel having the largest CW_(p) value. For eachchannel c_(j), N_(c) _(i) −N_(c) _(j) .

When the BS ceases a transmission on any one channel for which N_(c)_(i) has been determined, the BS reinitializes N_(c) for all channels.

1.8.4.2. Type B Multi-Channel Access Procedure

The BS may select a channel c_(i)∈C as follows.

-   -   The BS selects c_(j) uniformly randomly from C before each        transmission on multiple channels c_(i)∈C.    -   Or the BS does not select c_(j) more than once every one second.

Herein, C is a set of channels that the BS intends to transmit, i=01 . .. q−1, and q is the number of channels to be transmitted by the BS.

For a transmission on a channel c_(j), the BS performs channel access onthe channel c_(j) according to the procedure described in subclause1.8.3.1 along with the modification described in subclause 1.8.4.2.1. orsubclause 1.8.4.2.2.

For a transmission on the channel c_(i)·c_(j) among the channelsc_(i)∈C,

For each channel c_(i), the BS senses the channel c_(i) for at least asensing interval T_(mc)=25 us immediately before the transmission on thechannel c_(i). The BS may perform a transmission on the channel c_(i)immediately after sensing that the channel c_(i) is idle during at leastthe sensing interval T_(mc). When the channel is sensed as idle duringall time periods during which idle sensing is performed on the channelc_(j) within the given interval T_(mc), the channel c_(i) may beconsidered to be idle for T_(mc).

The BS does not continuously perform transmissions on the channelc_(i)·c_(j) (c_(i)∈C) for a period exceeding T_(mcot,p) as given inTable 15. T_(mcot,p) is determined using a channel access parameter usedfor the channel c_(j).

In the procedure of this subclause, the channel frequency of the channelset C selected by the gNB is one subset of a predefined channelfrequency set.

1.8.4.2.1. Type B1 Multi-Channel Access Procedure

A single CW_(p) value is maintained for a channel set C.

To determine CW_(p) for channel access on a channel c_(j), step 2 in theprocedure described in subclause 1.8.3.1 is modified as follows.

-   -   If at least 80% (Z=80%) of HARQ-ACK values corresponding to        PDSCH transmission(s) in reference subframe k of all channels        c_(i)∈C are determined to be NACK, then CW_(p) for all priority        classes p∈{1, 2, 3, 4} is incremented to the next higher allowed        value. Otherwise, the procedure goes to step 1.

1.8.4.2.2. Type B2 Multi-Channel Access Procedure

A CW_(p) value is maintained independently for each channel c_(i)∈C. Todetermine N_(init) for a channel c_(j), the CW_(p) value of the channelc_(j1)∈C is used. Herein, c_(j1) is a channel having the largest CW_(p)among all channels of the set C.

1.8.5. Uplink Channel Access Procedures

The UE and the BS that schedules a UL transmission for the UE performthe following procedure for access to a channel (on which LAA SCelltransmission(s) is performed). On the assumption that the UE and the BSare basically configured with a PCell that is a licensed band and one ormore Scells which are unlicensed bands, UL CAP operations applicable tothe present disclosure will be described below in detail, with theunlicensed bands represented as LAA SCells. The UL CAP operations may beapplied in the same manner even when only an unlicensed band isconfigured for the UE and the BS.

The UE may access a channel on which UL transmission(s) is performedaccording to a Type 1 or Type 2 UL CAP.

Table 12 illustrates that m_(p), a minimum CW, a maximum CW, an MCOT,and an allowed CW size applied to a CAP vary according to a channelaccess priority class.

TABLE 12 Channel Access Priority Class (p) m_(p) CW_(min,p) CW_(max,p)T_(ulmcot,p) allowed CW_(p) sizes 1 2 3 7 2 ms {3, 7} 2 2 7 15 4 ms {7,15} 3 3 15 1023 6 ms or 10 ms {15, 31, 63, 127, 255, 511, 1023} 4 7 151023 6 ms or 10 ms {15, 31, 63, 127, 255, 511, 1023} NOTE 1: For p =3,4,T_(ulmcot,p) = 10 ms if the higher layer parameterabsenceOfAnyOtherTechnology-r14 or absenceOfAnyOtherTechnology-r16 isprovided , otherwise, T_(ulmcot,p) = 6 ms. NOTE 2: When T_(ulmcot,p) = 6ms it may be increased to 8 ms by inserting one or more gaps. Theminimum duration of a gap shall be 100 us. The maximum duration beforeincluding any such gap shall be 6 ms.

1.8.5.1. Type 1 UL Channel Access Procedure)

This subclause describes a CAP performed by a UE, in which a timeduration spanned by sensing slots sensed to be idle before a ULtransmission(s) is random. This subclause is applicable to the followingtransmissions:

-   -   PUSCH/SRS transmission(s) scheduled and/or configured by the BS    -   PUCCH transmission(s) scheduled and/or configured by the BS    -   Transmission(s) related to a random access procedure (RAP)

FIG. 16 is a diagram illustrating a UL CAP for transmission in anunlicensed band to which various embodiments of the present disclosureare applicable.

The Type 1 UL CAP of the UE for transmission in the unlicensed band towhich various embodiments of the present disclosure are applicable maybe summarized as follows.

For a UL transmission, a transmission node (e.g., a UE) may initiate aCAP to operate in an unlicensed band (2110).

The UE may select a backoff counter N randomly within a CW according tostep 1. N is set to an initial value N_(init) (2120). N_(init) is avalue randomly selected between 0 and CW_(p).

Subsequently, when the backoff counter value N is 0 according to step 4(2130; Y), the UE ends the CAP (2132). The UE may then transmit a Txburst (2134). On the other hand, if the backoff counter value is not 0(2130; N), the UE decrements the backoff counter value by 1 according tostep 2 (2140).

Subsequently, the UE checks whether a channel is idle (2150). If thechannel is idle (2150; Y), the UE checks whether the backoff countervalue is 0 (2130).

On the contrary, if the channel is not idle, that is, the channel isbusy (2150; N), the UE checks whether the channel is idle during a deferduration T_(d) (of 25 usec or more) longer than a slot duration (e.g., 9usec) according to step 5 (2160). If the channel is idle for the deferduration (2170; Y), the UE may resume the CAP.

For example, if the backoff counter value N_(init) is 10 and the channelis determined to be idle after the backoff counter value is decrementedto 5, the UE senses the channel during the defer duration and determineswhether the channel is idle. If the channel is idle during the deferduration, the UE may perform the CAP again from the backoff countervalue 5 (or the backoff counter value 4 after decrementing the backoffcounter value by 1), instead of setting the backoff counter valueN_(init).

On the other hand, if the channel is busy during the defer duration(2170; N), the UE checks again whether the channel is idle during a newdefer duration by performing operation 2160 again.

If the UE has not performed a UL transmission on the channel on which ULtransmission(s) are performed after step 4 in the above procedure, theUE may perform the UL transmission on the channel, if the followingconditions are satisfied.

-   -   If the UE is ready to perform the transmission and the channel        is sensed to be idle during at least a sensing slot duration        T_(sl), and    -   If the channel has been sensed to be idle during all the slot        durations of a defer duration T_(d) immediately before the        transmission.

On the contrary, if the channel has not been sensed to be idle duringthe sensing slot duration T_(sl) when the UE first senses the channelafter it is ready to transmit, or if the channel has not been sensed tobe idle during any of the sensing slot durations of a defer durationT_(d) immediately before the intended transmission, the UE proceeds tostep 1 after sensing the channel to be idle during the slot durations ofthe defer duration T_(d).

The defer duration T_(d) includes a duration T_(f)(=16 us) immediatelyfollowed by m_(p) consecutive slot durations where each slot durationT_(sl) is 9 us, and T_(f) includes an idle slot duration T_(sl) at thestart of T_(f).

1.8.5.2. Type 2 UL Channel Access Procedure

If the UE is indicated to perform the Type 2A UL CAP, the UE uses theType 2A UL CAP for a UL transmission. The UE may perform thetransmission immediately after sensing the channel to be idle during atleast a sensing duration T_(short_ul)=25 us T_(short_ul) includes aduration T_(f)=16 us immediately followed by one slot sensing slotduration T_(sl)=9 us, and T_(f) includes a sensing slot at the start ofT_(f). The channel is considered to be idle for T_(short_ul), if twosensing slots within T_(short_ul) are sensed to be idle.

1.8.6. Channel Access Procedure for UL Multi-Channel Transmission(s)

If the UE

-   -   is scheduled to transmit on a channel set C, a UL scheduling        grant for the UL transmission on the channel set C indicates the        Type 1 CAP, and UL transmissions are scheduled to start at the        same time for all channels of the channel set C, and/or    -   if the UE intends to perform the UL transmission in resources        configured on the channel set C by the Type 1 CAP, and

the channel frequencies of the channel set C is one subset of apreconfigured channel frequency set:

-   -   The UE may perform the transmission on a channel c_(i)εC by the        Type 2 CAP.        -   If the Type 2 CAP has been performed on the channel c_(i)            immediately before the UE transmission on a channel c_(j)∈C            (herein, i·j), and        -   If the UE has accessed the channel c_(j) by using the Type 1            CAP,        -   Before performing the Type 1 CAP on any channel in the            channel set C, the UE uniformly randomly selects the channel            c_(j) from the channel set C.    -   If the UE fails to access any channel, the UE may not perform        the transmission on the channel c_(i)∈C within the bandwidth of        a carrier with a carrier bandwidth which has been scheduled or        configured by UL resources.

2 Random Access (RACH) Procedure

When a UE initially accesses a BS or has no radio resources for a signaltransmission, the UE may perform a random access procedure with the BS.

The random access procedure is used for various purposes. For example,the random access procedure may be used for initial network access in anRRC_IDLE state, an RRC connection reestablishment procedure, handover,UE-triggered UL data transmission, transition in an RRC INACTIVE state,time alignment establishment in SCell addition, OSI request, and beamfailure recovery. The UE may acquire UL synchronization and ULtransmission resources in the random access procedure.

Random access procedures may be classified into a contention-basedrandom access procedure and a contention-free random access procedure.The contention-based random access procedure is further branched into a4-step random access (4-step RACH) procedure and a 2-step random access(2-step RACH) procedure.

2.1. 4-Step RACH: Type-1 Random Access Procedure

FIGS. 17A and 17B are diagrams illustrating an exemplary 4-step RACHprocedure to which various embodiments of the present disclosure areapplicable.

When the (contention-based) random access procedure is performed in foursteps (4-step RACH procedure), the UE may transmit a message (Message 1(Msg1)) including a preamble related to a specific sequence on a PRACH(1701) and receive a PDCCH and a response message (RAR message) (Message2 (Msg2)) for the preamble on a PDSCH corresponding to the PDCCH (1703).The UE transmits a message (Message 3 (Msg3)) including a PUSCH based onscheduling information included in the RAR (1705) and perform acontention resolution procedure involving reception of a PDCCH signaland a PDSCH signal corresponding to the PDCCH signal. The UE may receivea message (Message 4 (Msg4)) including contention resolution informationfor the contention resolution procedure from the BS (1707).

The 4-step RACH procedure of the UE may be summarized in Table 13 below.

TABLE 13 Type of Signals Operations/ Information obtained 1^(st) stepPRACH preamble in UL * Initial beam acquisition * Random election ofRA-preamble ID 2^(nd) Step Random Access Response on DL-SCH * Timingalignment information * RA-preamble ID * Initial UL giant, TemporaryC-RNTI 3^(rd) Step UL transmission on UL-SCH * RRC connection request *UE identifier 4^(th) Step Contention Resolution on DL * Temporary C-RNTIon PDCCH for initial access * C-RNTI on PDCCH for UE in RRC_CONNECTED

In the random access procedure, the UE may first transmit an RACHpreamble as Msg1 on a PRACH.

Random access preamble sequences of two different lengths are supported.The longer sequence length 839 is applied to the SCSs of 1.25 kHz and 5kHz, whereas the shorter sequence length 139 is applied to the SCSs of15 kHz, 30 kHz, 60 kHz, and 120 kHz.

Multiple preamble formats are defined by one or more RACH OFDM symbolsand different CPs (and/or guard times). An RACH configuration for a cellis provided in system information of the cell to the UE. The RACHconfiguration includes information about a PRACH SCS, availablepreambles, and a preamble format. The RACH configuration includesinformation about associations between SSBs and RACH (time-frequency)resources. The UE transmits a RACH preamble in RACH time-frequencyresources associated with a detected or selected SSB.

An SSB threshold for RACH resource association may be configured by thenetwork, and an RACH preamble is transmitted or retransmitted based onan SSB having a reference signal received power (RSRP) measurementsatisfying the threshold. For example, the UE may select one of SSBssatisfying the threshold, and transmit or retransmit the RACH preamblein an RACH resource associated with the selected SSB. For example, whenretransmitting the RACH preamble, the UE may reselect one of the SSBsand retransmit the RACH preamble in an RACH resource associated with thereselected SSB. That is, the RACH resource for the retransmission of theRACH preamble may be identical to and/or different from the RACHresource for the transmission of the RACH preamble.

Upon receipt of the RACH preamble from the UE, the BS transmits an RARmessage (Msg2) to the UE. A PDCCH that schedules a PDSCH carrying theRAR is cyclic redundancy check (CRC)-masked by a random access radionetwork temporary identifier (RA-RNTI) and transmitted. Upon detectionof the PDCCH masked by the RA-RNTI, the UE may receive the RAR on thePDSCH scheduled by DCI carried on the PDCCH. The UE determines whetherthe RAR includes RAR information for its transmitted preamble, that is,Msg1. The UE may make the determination by checking the presence orabsence of the RACH preamble ID of its transmitted preamble in the RAR.In the absence of the response to Msg1, the UE may retransmit the RACHpreamble a predetermined number of or fewer times, while performingpower ramping. The UE calculates PRACH transmission power for thepreamble retransmission based on the latest pathloss and a power rampingcounter.

The RAR information may include a preamble sequence transmitted by theUE, a temporary cell RNTI (TC-RNTI) that the BS has allocated to the UEattempting random access, UL transmit time alignment information, ULtransmission power adjustment information, and UL radio resourceallocation information. Upon receipt of its RAR information on a PDSCH,the UE may acquire time advance information for UL synchronization, aninitial UL grant, and a TC-RNTI. The timing advance information is usedto control a UL signal transmission timing. For better alignment betweena PUSCH/PUCCH transmission of the UE and a subframe timing of a networkend, the network (e.g., the BS) may measure the time difference betweena PUSCH/PUCCH/SRS reception and a subframe and transmit the timingadvance information based on the time difference. The UE may transmit aUL signal as Msg3 of the random access procedure on a UL-SCH based onthe RAR information. Msg3 may include an RRC connection request and a UEID. The network may transmit Msg4 in response to Msg3. Msg4 may betreated as a contention resolution message on DL. As the UE receivesMsg4, the UE may enter an RRC_CONNECTED state.

As described before, the UL grant included in the RAR schedules a PUSCHtransmission to the BS. A PUSCH carrying an initial UL transmissionbased on the UL grant of the RAR is referred to as an Msg3 PUSCH. Thecontent of the RAR UL grant starts from the most significant bit (MSB)and ends in the least significant bit (LSB), given as Table 14.

TABLE 14 Number of RAR UL grant field bits Frequency hopping flag 1 Msg3PUSCH frequency resource 12 allocation Msg3 PUSCH time resourceallocation 4 Modulation and coding scheme (MCS) 4 Transmit power control(TPC) for 3 Msg3 PUSCH CSI request 1

A transmit power control (TPC) command is used to determine thetransmission power of the Msg3 PUSCH. For example, the TPC command isinterpreted according to Table 15.

TABLE 15 TPC command value [dB] 0 −6 1 −4 2 −2 3 0 4 2 5 4 6 6 7 8

2.2. 2-Step RACH: Type-2 Random Access Procedure

FIG. 18 is a diagram illustrating an exemplary 2-step RACH procedure towhich various embodiments of the present disclosure are applicable.

The (contention-based) RACH procedure performed in two steps, that is,the 2-step RACH procedure has been proposed to simplify the RACHprocedure and thus achieve low signaling overhead and low latency.

In the 2-step RACH procedure, the operation of transmitting Msg1 and theoperation of transmitting Msg3 in the 4-step RACH procedure may beincorporated into an operation of transmitting one message, Message A(MsgA) including a PRACH and a PUSCH by the UE. The operation oftransmitting Msg2 by the BS and the operation of transmitting Msg4 bythe BS in the 4-step RACH procedure may be incorporated into anoperation of transmitting one message, Message B (MsgB) including an RARand contention resolution information.

That is, in the 2-step RACH procedure, the UE may combine Msg1 and Msg3of the 4-step RACH procedure into one message (e.g., MsgA) and transmitthe message to the BS (1801).

Further, in the 2-step RACH procedure, the BS may combine Msg2 and Msg4of the 4-step RACH procedure into one message (e.g., MsgB) and transmitthe message to the UE (1803).

The 2-step RACH procedure may become a low-latency RACH procedure basedon the combinations of these messages.

More specifically, MsgA may carry a PRACH preamble included in Msg1 anddata included in Msg3 in the 2-step RACH procedure. In the 2-step RACHprocedure, MsgB may carry an RAR included in Msg2 and contentionresolution information included in Msg4.

2.3. Contention-Free RACH

FIG. 19 is a diagram illustrating an exemplary contention-free RACHprocedure to which various embodiments of the present disclosure areapplicable.

The contention-free RACH procedure may be used for handover of the UE toanother cell or BS or may be performed when requested by a BS command.The contention-free RACH procedure is basically similar to thecontention-based RACH procedure. However, compared to thecontention-based RACH procedure in which a preamble to be used israndomly selected from among a plurality of RACH preambles, a preambleto be used by the UE (referred to as a dedicated RACH preamble) isassigned to the UE by the BS in the contention-free RACH procedure(1901). Information about the dedicated RACH preamble may be included inan RRC message (e.g., a handover command) or provided to the UE by aPDCCH order. When the RACH procedure starts, the UE transmits thededicated RACH preamble to the BS (1903). When the UE receives an RARfrom the BS, the RACH procedure is completed (1905).

In the contention-free RACH procedure, a CSI request field in an RAR ULgrant indicates whether the UE is to include an aperiodic CSI report ina corresponding PUSCH transmission. An SCS for the Msg3 PUSCHtransmission is provided by an RRC parameter. The UE may transmit thePRACH and the Msg3 PUSCH in the same UL carrier of the same servingcell. A UL BWP for the Msg3 PUSCH transmission is indicated by SIB 1.

3. Various Embodiments of the Present Disclosure

A detailed description will be given of various embodiments of thepresent disclosure based on the above technical ideas. Theafore-described contents of clause 1 and clause 2 are applicable tovarious embodiments of the present disclosure described below. Forexample, operations, functions, terminologies, and so on which are notdefined in various embodiments of the present disclosure may beperformed and described based on clause 1 and clause 2.

Symbols/abbreviations/terms used in the description of variousembodiments of the present disclosure may be defined as follows.

-   -   CBRA: contention-based random access    -   CDM: code division multiplexing (code domain sharing)        -   comb: mapping of a signal at predetermined intervals in the            frequency domain. For example, comb 2 (comb-2 or 2-comb) may            mean that the same specific DMRS port is mapped to each of            REs apart from each other by two subcarriers. For example,            comb 4 (comb-4 or 4-comb) may mean that the same specific            DMRS port is mapped to each of REs apart from each other by            four subcarriers.    -   CP-OFDM: cyclic prefix based orthogonal frequency division        multiplex    -   DFT-s-OFDM: discrete Fourier transform spread orthogonal        frequency division multiplex    -   DL: downlink    -   DM-RS (DMRS): demodulation reference signal    -   FDM: frequency division multiplexing (frequency domain sharing)    -   MCS: modulation and coding scheme    -   OCC: orthogonal cover code    -   OFDM: orthogonal frequency division multiplexing    -   PAPR: peak to average power ratio    -   PRACH: physical random access channel    -   PRB: physical resource block    -   PUSCH: physical uplink shared channel    -   RA: random access    -   RACH: random access channel    -   RAPID: random access preamble identifier    -   RAR: random access response    -   RB: resource block    -   RE: resource element    -   RNTI: radio network temporary identifier    -   RO: RACH occasion or PRACH occasion    -   TDM: time division multiplexing (time domain sharing)    -   UL: uplink

As more and more communication devices have required larger trafficalong the trend of the times, a wireless wideband communication systemadvanced from the LTE system, that is, the next-generation 5G system isrequired. This next-generation 5G system is called new RAT (NR), forconvenience.

The NR system may support the 2-step RACH procedure in addition to the4-step RACH procedure.

In the 2-step RACH procedure, MsgA may include a PRACH preamble includedin Msg1 and data (a PUSCH) included in Msg3. In the 2-step RACHprocedure, MsgB may include an RAR included in Msg2 and contentionresolution information included in Msg4.

In the 2-step RACH procedure, for example, the UE may transmit the PRACHpreamble and the PUSCH without performing timing advance (TA) during aUL transmission. For example, since TA is not performed, the receptiontimings of signals received from the BS may be different. For example,when the reception timings between the received signals do not match,the receiver attempts to restore the signals by detecting the startingpoints of the signals, and interference (e.g., inter-symbol interferenceand/or inter-carrier interference) may occur between the signals,thereby degrading signal quality. For example, interference signalsgenerated between the signals with mismatched reception timings maydegrade the detection performance of MsgA (PRACH preamble+PUSCH) in the2-step RACH procedure.

In this regard, various embodiments of the present disclosure mayprovide a method and apparatus for multiplexing PUSCHs and mapping aDMRS in MsgA (PRACH preamble+PUSCH) to support a 2-step RACH procedure.

FIG. 20 is a simplified diagram illustrating a method of operating a UEand a BS according to various embodiments of the present disclosure.

FIG. 21 is a simplified diagram illustrating a method of operating a UEaccording to various embodiments of the present disclosure.

FIG. 22 is a simplified diagram illustrating a method of operating a BSaccording to various embodiments of the present disclosure.

Referring to FIGS. 20 to 22, the UE may obtain/generate MsgA inoperations 2001 and 2101 according to an exemplary embodiment. Forexample, the UE may obtain/generate MsgA based on mapping of a PRACHpreamble to an RACH occasion (RO) and/or mapping of a PUSCH to a PUSCHoccasion and/or mapping of a DMRS.

The UE may transmit MsgA and the BS may receive MsgA in operations 2003,2103, and 2201 according to an exemplary embodiment.

The BS may decode (detect) MsgA in operations 2005 and 2203 according toan exemplary embodiment. For example, the BS may obtain the PRACHpreamble and/or the PUSCH and/or the DMRS included in MsgA by decodingMsgA.

The BS may transmit MsgB and/or Msg2 in response to MsgA and the UE mayreceive MsgB and/or Msg2 in operations 2007, 2105, and 2205 according toan exemplary embodiment.

More specific operations, functions, terms, and so on in the operationsof each exemplary embodiment may be performed and described based on thefollowing various embodiments of the present disclosure.

A detailed description will be given below of various embodiments of thepresent disclosure. Unless contradicting each other, the variousembodiments of the present disclosure described below may be combinedfully or partially to form other various embodiments of the presentdisclosure, which may be clearly understood by those skilled in the art.

3.1. Multiplexing Schemes for PUSCH

3.1.1. Multiplexing

Various embodiments of the present disclosure may provide multiplexingschemes (e.g., frequency division multiplexing (FDM), time divisionmultiplexing (TDM), code division multiplexing (CDM), or a combinationof two or more of them) for MsgA.

For example, UL coverage and/or channel estimation and/or inter-symbolinterference and/or inter-carrier interference and/or resourceutilization may be considered.

For example, in the case of CDM (e.g., PUSCHs included in MsgA aremultiplexed in CDM), particularly inter-layer interference caused bytime misalignment may be considered.

For example, in the 4-step RACH procedure, a PUSCH for Msg3 may beallocated by a UL grant in an RAR message (Msg2).

For example, corresponding resources may be allocated in an FDM and/orTDM manner.

Further, for example, for the PUSCH of Msg3, since a single symbolfront-loaded DMRS of configuration type 1 on DMRS port 0 is used and theremaining REs of the symbols are not used for any PUSCH transmission,the PUSCH may be allowed for a single UE.

For example, in the 2-step RACH procedure, a PRACH preamble and/or aPUSCH may be included in MsgA.

Similarly, for example, FDM/TDM resource allocation may be allowed forPUSCHs for MsgA.

FIGS. 23A to 23D are diagrams illustrating an exemplary configuration ofMsgA according to various embodiments of the present disclosure.

In FIGS. 23A to 23D, the horizontal axis may correspond to the timedomain or the time axis, and the vertical axis may correspond to thefrequency domain or the frequency axis. For example, the time domain maycorrespond to one or more slots and/or one or more OFDM symbols, and thefrequency axis may correspond to one or more RBs and/or one or more REs.

For example, PUSCHs and/or PUSCH occasions for MsgA may be multiplexedin various manners.

For example, FIG. 23A illustrates an example in which PUSCHs and/orPUSCH occasions for MsgA are multiplexed in FDM.

For example, FIG. 23B illustrates an example in which PUSCHs and/orPUSCH occasions for MsgA are multiplexed in TDM.

For example, FIG. 23C illustrates an example in which PUSCHs and/orPUSCH occasions for MsgA are multiplexed in FDM and TDM.

For example, FIG. 23D illustrates an example in which PUSCHs and/orPUSCH occasions for MsgA are multiplexed in FDM and CDM.

For example, in an FDM case (e.g., when PUSCHs and/or PUSCH occasionsare multiplexed in FDM), a narrow bandwidth and (relatively) many OFDMsymbols (e.g., a threshold number of or more OFDM symbols/more OFDMsymbols than the threshold number) may be allocated as a PUSCH and/orPUSCH occasion resource.

In this case, for example, use of multiple OFDM symbols may lead to ULcoverage enhancement. However, for example, a PUSCH resource includingDMRS REs and data REs may suffer from inter-carrier interference from anadjacent PUSCH resource.

For example, in a TDM case (e.g., when PUSCHs and/or PUSCH occasions aremultiplexed in TDM), a wide bandwidth and a (relatively) small number ofOFDM symbols (e.g., a threshold number of or fewer OFDM symbols/fewerOFDM symbols than the threshold number) may be allocated as a PUSCHand/or PUSCH occasion resource.

In this case, for example, a frequency diversity gain may be obtainedfrom the wide bandwidth. However, for example, UE coverage may belimited in view of the small number of OFDM symbols, and a PUSCHresource may suffer from inter-symbol interference from an adjacentPUSCH symbol.

Further, for example, since PUSCH resources are orthogonally designatedin both the FDM case and the TDM case, when the UE does not selectpreserved/reserved PUSCH resources, the unselected resources may bewasted.

For example, in a CDM case (e.g., when PUSCHs and/or PUSCH occasions aremultiplexed in CDM), a wide bandwidth and (relatively) many OFDM symbols(e.g., a threshold number of or more OFDM symbols/more OFDM symbols thanthe threshold number) may be allocated as a PUSCH and/or PUSCH occasionresource.

In this case, for example, UL coverage may be enhanced. Further, forexample, inter-carrier interference and inter-symbol interference may bereduced. Further, for example, resource utilization efficiency may beincreased. However, for example, inter-layer interference may need to beconsidered, particularly in the case of time misalignment.

3.1.2. Resource Indication

According to various embodiments of the present disclosure, a PUSCHresource group associated with a specific RO may be indicated.

For example, as many PUSCH resources as the number of (P)RACH preamblesused for contention-based random access (CBRA) may be configured in anRO.

For example, let the number of (P)RACH preambles for CBRA per RO bedenoted by M and the maximum number of multiplexible RAPIDs per PUSCHresource be denoted by N. Then, at least M/N PUSCH resources may berequired. For example, a group of the PUSCH resources may be indicated.For example, the configuration of the PUSCH resources and the RO may beindicated by a mapping indicator.

That is, according to various embodiments of the present disclosure, theBS may transmit configuration information about PUSCH occasions fortransmission of PUSCHs included in MsgA to the UE, and the UE may mapand transmit a PUSCH for MsgA based on the configuration information.

For example, the configuration information may include a time-domainindicator and/or a frequency-domain indicator.

For example, the time-domain indicator may be an indicator indicatingtime resources of the PUSCH occasions for transmission of the PUSCHsincluded in MsgA.

For example, the frequency-domain indicator may be an indicatorindicating frequency resources of the PUSCH occasions for transmissionof the PUSCHs included in MsgA.

For example, the time-domain indicator may include one or more pieces ofthe following information.

-   -   Number of OFDM symbols per PUSCH resource (and/or Occasion): {1,        . . . 14}        -   That is, the number of OFDM symbols per PUSCH resource            (and/or PUSCH occasion) may be indicated by the            configuration information. The number of OFDM symbols may be            1 to 14.    -   The positions of PUSCH resources (and/or occasions) in a slot        -   Bitmap, and/or            -   Starting OFDM symbols/, and/or                -   That is, the starting OFDM symbols of the PUSCH                    resources (and/or PUSCH occasions) in the time                    domain may be indicated by the configuration                    information.        -   The number of consecutive PUSCH occasions in the time domain            in the slot.    -   Indicator indicating whether a null OFDM symbol is included in a        PUSCH occasion.        -   A null OFDM symbol may refer to an OFDM symbol to which no            PUSCH is mapped. A null OFDM symbol may be configured            between PUSCH occasions in the time domain. In the presence            of a null OFDM symbol between PUSCH occasions, the            consecutive PUSCH occasions in the time domain may be            understood as separated by the null OFDM symbol. That is,            the null OFDM symbol may be understood as a time gap in the            time domain.    -   Slot indexes to which a PUSCH resource group is mapped        -   Bitmap, and/or        -   Individual slot indexes, and/or        -   Starting slot index, and/or        -   The number of consecutive slots

For example, the frequency-domain indicator may include one or morepieces of the following information.

-   -   The number of PRBs        -   The number of PRBs for the PUSCH resources (and/or PUSCH            occasions) may be indicated by the configuration            information.    -   Indicator indicating continuous mapping or non-continuous        mapping        -   That is, the configuration information may indicate whether            the PUSCH resources (and/or PUSCH occasions) are            continuously or non-continuously mapped in the frequency            domain. For example, for non-continuous mapping, an            interlace structure in a shared spectrum or an unlicensed            band may be considered.    -   The positions of the PUSCH resources (and/or occasions) in the        frequency domain        -   Starting PRBs, and/or        -   The number of consecutive PUSCH resources (and/or PUSCH            occasions) and/or        -   Bitmap or the like    -   Indicator indicating whether a null PRB is included in a PUSCH        occasion        -   A null PRB may refer to a PRB to which no PUSCH is mapped. A            null PRB may be configured between PUSCH occasions in the            frequency domain. In the presence of a null PRB between            PUSCH occasions, the consecutive PUSCH occasions in the            frequency domain may be understood as separated by the null            PRB. That is, the null PRB may be understood as a frequency            gap in the frequency domain.

Further, for example, an indicator indicating mapping between an ROgroup and a PUSCH resource (and/or PUSCH occasion) group may indicate aconfiguration relationship.

3.2. Multiple Preamble to Single PUSCH Resource

3.2.1. Association Between DMRS and RAPID

According to various embodiments of the present disclosure, when CDM isallowed for PUSCHs included in MsgA, a plurality of RAPIDs maycorrespond to one PUSCH resource.

-   -   For example, a plurality of DMRS resources and/or sequences        and/or a plurality of scrambling sequences may be used.    -   For example, a certain DMRS resource and/or sequence and/or        scrambling sequence may be associated with an RAPID.

For example, in the 4-step RACH procedure, a PUSCH included in Msg3 maybe allocated by a UL grant associated with an RAPID.

Similarly, for example, in the 2-step RACH procedure, a PUSCH includedin MsgA may be designated for each RAPID for the FDM and TDM cases.Further, for example, when CDM is allowed, there is a need for allowingcorrespondence between one PUSCH resource and a plurality of RAPIDs. Inthis case, for example, a plurality of DMRS resources and/or sequencesand/or scrambling sequences may be required to decouple a plurality ofdata mixed in the PUSCH resource.

Further, for example, a certain DMRS resource and/or sequence and/orscrambling sequence may be associated with an RAPID.

3.2.2. Parameters for MsgA PUSCH

In this subclause and the description of various embodiments of thepresent disclosure, DMRS port and DMRS sequence may be collectivelyreferred to as DMRS resource. For example, one or more DMRS sequencesmay be mapped to one DMRS port. For example, one or more DMRS ports maybe mapped to one DMRS sequence. For example, DMRS ports may be mapped toDMRS sequences in a 1:1, M:1, or 1:M correspondence (M is a naturalnumber).

According to various embodiments of the present disclosure, whenresources are configured for PUSCHs included in MsgA (MsgA PUSCHs) inthe 2-step RACH procedure, the maximum number of RAPIDs and/or themaximum number of UEs, which may be multiplexed in each MsgA PUSCH maybe designated/configured.

Further, for example, the number of DMRS resources (ports) and/or DMRSsequences may be determined according to the maximum number of RAPIDswhich may be multiplexed in any MsgA PUSCH.

For example, the number may be designated/configured by each parameter.For example, the maximum number of antenna ports and the maximum numberof sequences may be designated/configured.

For example, the BS may provide the following parameters to the UE.

Parameters for MsgA PUSCH:

-   -   Maximum number of RAPIDs: for example, 1, 2, 4, 8    -   Maximum number of antenna ports for DMRS: for example, 1, 2, 4    -   Maximum number of sequences: for example, 1, 2

For example, the maximum number of RAPIDs multiplexed (in a MsgA PUSCH)may be configured for the UE in consideration of coverage and/orgeometry by the network.

For example, in a small cell (e.g., when the 2-step RACH procedure isperformed in a small cell), the maximum number of multiplexed RAPIDs maybe relatively large. For example, because the probability ofmisalignment between reception synchronizations is relatively small in asmall cell, signals are highly likely to be received within a fastFourier transform (FFT) boundary, and the geometry also has a goodvalue, relatively many users may be multiplexed. For example, whenrandom access does not occur often, the efficiency of PUSCH resourcesmay be increased by increasing the number of RAPIDs that may be mappedto each PUSCH resource.

On the contrary, for example, in the case of wide coverage (e.g., whenthe 2-step RACH procedure is performed in wide coverage), the maximumnumber of multiplexed RAPIDs may be relatively small. For example,particularly when users within so wide coverage as to require DFT-s-OFDMare accommodated, reception sensitivity may be significantly lowered andthe probability of misalignment between reception synchronizations isrelatively increased. Accordingly, the number of users and/or RAPIDsmultiplexed in a PUSCH resource is preferably reduced relatively.

3.2.2.1. PUSCH Data Scrambling Sequence

According to various embodiments of the present disclosure, a differentPUSCH data scrambling sequence may be obtained for/applied to each UE.For example, when an MsgA PUSCH resource is used for a plurality of UEs,a different sequence may be generated and applied (to each UE (user)) toreduce interference between UEs (users).

For example, for a UE which has not initially accessed or a UE whichdoes not have a UE-specific RNTI, an RA-RNTI or an RNTI used to monitora response (of the BS) for an MsgA PUSCH may be used as a seed valueused to generate/obtain a scrambling sequence. Further, for example,information (e.g., an RAPID) associated with a PRACH preamble selectedby a UE (or user) may be used as the seed of a scrambling sequence, sothat the UE (user) may be identified.

For example, when an RNTI (e.g., TC-RNTI or C-RNTI) is allocated to a UEafter initial access, the UE may use its RNTI. For example, the UE mayuse the allocated RNTI as the seed value of a scrambling sequence.

According to the above-described various embodiments of the presentdisclosure, the user or UE may be identified (particularly in a datachannel region) based on the seed value (e.g., RAPID) of thecorresponding scrambling sequence.

For example, a mapping relationship between PRACH preambles and PUSCHs(PUSCH occasions) (and/or DMRS resources in the PUSCHs (PUSCHoccasions)) may be preconfigured.

For example, one or more PRACH preambles may be mapped to one PUSCH(occasion) (and/or a DMRS resource in the PUSCH (occasion)).

For example, one PRACH preamble may be mapped to one or more PUSCHs(PUSCH occasions) (and/or DMRS resources in the PUSCHs (PUSCHoccasions)). For example, PRACH preambles may be mapped to PUSCHs (PUSCHoccasions) in a 1:1, M:1, or 1:M correspondence (M is a natural number).

Accordingly, for example, particularly when PRACH preambles are mappedM:1 to PUSCHs (PUSCH occasions) (and/or DMRS resources in the PUSCHs(PUSCH occasions)), identification of users/UEs which have transmitted(PUSCHs in) MsgA may be problematic.

According to the above-described various embodiments of the presentdisclosure, UEs which have selected different PRACH preamblesobtain/generate PUSCHs based on different RAPIDs. Therefore, uponreceipt of MsgA, the BS may decode/demodulate the PUSCHs based on theRAPIDs corresponding to the PRACH preambles and identify the UEsaccording to success or failure of the decoding/modulation.

For example, a scrambling sequence generator used to generate a PUSCH(or for a PUSCH) may be initialized by the following Equation 1. One ormore of parameters used in Equation 1 may begenerated/obtained/determined based on various embodiments of thepresent disclosure.

$\begin{matrix}{c_{init} = \left\{ \begin{matrix}{{n_{RNTI} \cdot 2^{16}} + {n_{RAPID} \cdot 2^{10}} + n_{ID}} & {{for}\mspace{14mu}{msgA}\mspace{14mu}{on}\mspace{14mu} P\; U\; S\; C\; H} \\{{n_{RNTI} \cdot 2^{15}} + n_{ID}} & {{otherw}i{se}}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In Equation 1, Cinit may represent an initial value for the scramblingsequence generator.

The value of each parameter may be determined as follows.

-   -   When the RNTI is a C-RNTI, a modulation and coding scheme C-RNTI        (MCS-C-RNTI), a semi-persistent channel state information RNTI        (SP-CSI-RNTI), or a configured scheduling RNTI (CS-RNTI), the        (PUSCH) transmission is not scheduled by DCI format 1_0 in a        common search space, and a higher layer parameter        dataScramblingIdentityPUSCH is set, n_(ID)∈{0, 1, . . . , 1023}        may have a value indicated by the higher layer parameter        dataScramblingIdentityPUSCH.    -   When the (PUSCH) transmission is triggered by the 2-step RACH        procedure and a higher-layer parameter        msgA-dataScramblingIdentity is set, n_(ID)∈{0, 1, . . . , 1023}        may have a value indicated by the higher layer parameter        msgA-dataScramblingIdentity.    -   Otherwise, n_(ID)=N_(ID) ^(cell). That is, n_(ID) may have the        same value as a physical cell identifier (PCI). For example, the        value may range from 0 to 1007.    -   η_(RAPID) may be the index of a PRACH preamble transmitted for        MsgA. For example, n_(RAPID), which is the seed value of a        scrambling sequence, may correspond to information associated        with the PRACH preamble selected by the UE (or user). The user        may be identified by n_(RAPID).    -   n_(RNTI) may have the same value as the RA-RNTI for MsgA (when        for the PUSCH included in MsgA). For example, as the seed value        of the scrambling sequence, n_(RNTI) may correspond to the above        RNTI or the RNTI used to monitor a response (of the BS) to the        PUSCH of MsgA. In another example, it may have the same value as        an RA-RNTI for the 4-step RACH procedure.

For example, inter-cell interference may be randomized by n_(ID).

For example, there may be an RA-RNTI and an msgB-RNTI corresponding to aspecific RO in the 2-step RACH procedure.

According to various embodiments of the present disclosure, the RA-RNTImay be used to generate/obtain a PUSCH data scrambling sequence, and themsgB-RNTI may be used to monitor a PDCCH for MsgB.

That is, according to various embodiments of the present disclosure, theRA-RNTI and the msgB-RNTI corresponding to the specific RO may be usedfor different purposes.

In addition, according to various embodiments of the present disclosure,the RA-RNTI and the RAPID may be distinguished and used as a seed valuefor generating/obtaining a PUSCH data scrambling sequence.

3.2.2.2. DM-RS Sequence/DM-RS Resource

For example, a scrambling sequence described above in subclause 3.2.2.1may be related to scrambling of data of a PUSCH included in MsgA,whereas a DMRS sequence described below in subclause 3.2.2.2 may berelated to generation of an RS for demodulation of a PUSCH included inMsgA.

For example, a REL.15 NR UL DMRS sequence may be designed by using abase sequence (e.g., a gold sequence for CP-OFDM, a low-peak to averagepower ratio (PAPR) sequence for transform precoding, or the like) and anorthogonal cover code (OCC).

For example, a base sequence and an OCC may be applied to (a DMRSsequence of) a PUSCH included in MsgA. However, for example, in the caseof time mismatch, it may be necessary to discuss whether the OCC may beapplied to the DMRS sequence of the PUSCH included in MsgA. Further, forexample, a method of selecting an initialization seed value for a basesequence may need to be discussed.

For example, two types of physical layer resources (e.g.,dmrs-TypeA-Position (comb-2) and dmrs-TypeB-Position) may be defined forthe REL.15 NR UL DMRS sequence.

For example, dmrs-TypeA-Position may be a parameter related to DMRSmapping type A. For example, in DMRS mapping type A, the first DMRS maybe located in symbol 2 or 3 in a slot and mapped relative to the startof a slot boundary regardless of the starting position of an actual datatransmission in the slot. For example, dmrs-TypeA-Position=ENUMERATED{pos2, pos3}, which may indicate the position of the first DMRS.

For example, dmrs-TypeB-Position may be a parameter related to DMRSmapping type B. For example, in DMRS mapping type B, the first DM-RS maybe located in the first symbol of a data allocation area.

For example, like Msg 3 of the 4-step RACH procedure,dmrs-TypeA-Position may be applied to a PUSCH included in MsgA. In thiscase, for example, whether both sets of frequency resources (e.g., (aset of) even-numbered REs and (a set of) odd-numbered REs) are availableas DMRS physical layer resources for the PUSCH included in MsgA may needto be discussed.

For example, the use of both sets for the DMRS of the PUSCH included inMsgA may have various advantages.

For example, when the use of both sets is allowed, a relatively largenumber of UEs may be multiplexed in the PUSCH resources.

Further, for example, in the case where the use of both sets is allowed,when two PUSCH resources having different lengths of frequency resourcesare multiplexed, different frequency resource sets may be allocated asDMRS physical resources for each PUSCH resource. Accordingly, betterchannel estimation performance may be provided.

Various embodiments of the present disclosure may relate to a method ofgenerating/obtaining a DMRS sequence. Further, various embodiments ofthe present disclosure may relate to a method of utilizing DMRSresources.

For example, when CDM is allowed for PUSCHs included in MsgA, it may berelated to the utilization of DMRS resources and sequences.

-   -   For example, it may be related to whether an OCC may be applied        to the DMRS sequence of a PUSCH included in MsgA.    -   For example, it may be related to a method of selecting an        initialization seed value for a base sequence (e.g., a gold        sequence for CP-OFDM, a low-PAPR sequence for transform        precoding, or the like).    -   For example, it may be related to whether two sets of frequency        resources (e.g., (a set of) even-numbered REs and (a set of)        odd-numbered REs) may be used as physical resources for the DMRS        in a PUSCH included in MsgA.

According to various embodiments of the present disclosure, a method ofgenerating/obtaining a DMRS sequence based on the waveform of a PUSCHincluded in MsgA may be provided.

For example, when CP-OFDM is set as the waveform of the PUSCH includedin MsgA, the seed value of the DMRS sequence may be selected from a setof parameters for MsgA.

For example, where the number of corresponding seed values is 2 orlarger, a seed value may be selected according to an RAPID.

For example, when DFT-s-OFDM is set as the waveform of MsgA, a low-PAPRsequence may be used as the DMRS sequence. For example, one designatedor indicated base sequence may be used.

For example, when CP-OFDM is set as the waveform of the PUSCH in MsgA(e.g., when transform precoding is disabled), one or more DMRS sequencesmay be used. For example, because the maximum number of DMRS sequencesmay be {1, 2}, for example, referring to Parameters for MsgA PUSCHdescribed in subclause 3.2.2., when CP-OFDM is set as the waveform ofthe MsgA PUSCH, the maximum number of DMRS sequences may be 1 or 2.Further, for example, when CP-OFDM is set as the waveform of the MsgAPUSCH, the number of seed values for the DMRS sequence may be 2 orlarger.

For example, when DFT-s-OFDM is set as the waveform of the MsgA PUSCH(e.g., transform precoding is enabled), one DMRS sequence may be used.

In the above-described various embodiments of the present disclosure,the seed value of a DMRS sequence may be used as a parameter forinitialization of a scrambling sequence generator used when transformprecoding is disabled/enabled.

3.2.2.3. DM-RS Antenna Port

For example, when reception synchronization does not match betweenreceived signals in a situation in which a plurality of UEs (users) aremultiplexed, channel estimation performance obtained using the DMRS maybe degraded. However, the degree of degradation may vary depending on(antenna) port selection, and the channel estimation performance mayalso vary depending on the (antenna) port selection.

For example, PUSCH DMRS frequency resources are configured in a 2-combform, and the resources of each comb may include phase components thatcreate time-domain CSs of 0 and FFT/2. For example, when the differencein reception time between OFDM symbols transmitted by UEs (users) usingdifferent frequency resources is out of a CP range (e.g., 4 us),inter-carrier interference may occur. On the other hand, even when thedifference in reception time between OFDM symbols transmitted by usersusing different CS values in the same frequency resources is out ofFFT/8 (66.667/8 us 8.8 us), the influence of inter-OFDM symbolinterference may not be significant.

According to various embodiments of the present disclosure, when a TypeA DMRS is for one OFDM symbol (e.g., a Type A DMRS is mapped to andtransmitted/received in one OFDM symbol), a total of 4 antenna ports maybe used:

-   -   For example, when the number of antenna ports is set to 4, all        available antenna ports may be used, and/or    -   For example, when the number of antenna ports is set to 2,        antenna ports (e.g., 0 and 1 or 2 and 3) having different CSs in        a specific frequency resource may be used, and/or    -   For example, when the number of antenna ports is set to 1, an        antenna port (e.g., 0 or 1, or 2 or 3) having a specific        frequency resource and a specific CS may be used.

In this case, according to various embodiments of the presentdisclosure, when the number of DMRS sequences is 2 or larger, the numberof available DMRS sequences per antenna port may be 2 or larger.

According to various embodiments of the present disclosure, the maximumnumber of multiplexable RAPIDs may be determined in consideration of thenumber of DMRS ports and the number DMRS sequences.

According to various embodiments of the present disclosure, each RAPID(and/or PRACH preamble) may be mapped to a PUSCH occasion (a DMRSresource in the PUSCH occasion). Herein, a DMRS port index may beconsidered first in ascending order and then, a DM-RS sequence index maybe considered in ascending order.

For example, given DMRS ports {0, 1, 2, 3} and a DMRS sequence {a, b},each RAPID is mapped in the order of DMRS sequence a, b in DMRS port0->DMRS sequence a, b in DMRS port 1->DMRS sequence a, b in DMRS port2->DMRS sequence a, b in DMRS port 3. Since an RAPID is related to theindex of a PRACH preamble included in MsgA, this example may also beunderstood as an example of resource mapping of each PRACH preamble.

For example, when one or more PRACH preambles are mapped to a (valid)PUSCH occasion, the PRACH preambles may be mapped in ascending order ofDMRS indexes in the PUSCH occasion. Herein, the DMRS indexes may bedetermined by first considering the DMRS port indexes in ascending orderand then the DMRS sequences in ascending order.

According to various embodiments of the present disclosure, whenselecting a PRACH preamble for the 2-step RACH procedure, a UE mayrandomly select one of ROs in a specific duration and randomly select apreamble.

Additionally, according to various embodiments of the presentdisclosure, the UE may randomly select a specific RO and then select apreamble in the selected RO in multiple steps.

For example, the UE may select one of configured RAPID groups accordingto the number of DMRS sequences and then select a specific RAPID fromthe selected RAPID group. According to these various embodiments of thepresent disclosure, for example, the RAPID may be selected in the orderof better channel estimation obtained from the DMRS.

3.3. MCS Level

According to various embodiments of the present disclosure, a verylimited number of MCS levels are available for a PUSCH included in MsgA.

According to various embodiments of the present disclosure, whenmultiple sets of DMRS frequency resources are allowed, each DMRSfrequency resource may be associated with an MCS level.

3.3.1. MCS Level Related to MsgA PUSCH

For example, in the 4-step RACH procedure, an MCS for Msg3 may beobtained based on a UL grant included in an RAR message. Accordingly,for example, the BS may set an MCS in a low index to high index orderaccording to the channel state of the UE. Further, for example,time/frequency resources may be allocated to a PUSCH (included in Msg3)based on the selected MCS level and/or required coverage.

In contrast, for example, in the 2-step RACH procedure, it may bedifficult to select an MCS flexibly. For example, when the UE selects anMCS level for a UL transmission according to a DL measurement result,the UE may have difficulty in applying the MCS level to the ULtransmission because a DL channel and a UL channel differ greatly interms of interference levels as well as channel states.

Moreover, for example, the amount of PUSCH resources required for MsgAmay be changed according to an MCS level. Therefore, for example, whenseveral MCS levels are allowed, may types of PUSCH resources should bedefined and/or preconfigured, which may not be preferable in terms ofresource utilization.

In this context, for example, it may be preferable to use a very limitednumber of MCS levels for a PUSCH included in MsgA. For example, oneand/or two MCS levels may be available for the PUSCH included in MsgA.For example, only QPSK for CP-OFDM may be applied to the PUSCH includedin MsgA, and two types of coding rates may be available for the PUSCHincluded in MsgA.

According to various embodiments of the present disclosure, whenmultiple MCS levels are allowed for transmission of the PUSCH (includedMsgA), a plurality of types of PUSCH resources may be defined accordingto the MCS levels. For example, an RAPID may be associated with an MCSlevel.

The above will be described below in greater detail.

As described above, for example, when multiple MCS levels are allowedfor transmission of the PUSCH (included MsgA), a plurality of types ofPUSCH resources may be defined according to the MCS levels.

Therefore, for example, when a PUSCH resource corresponds to an RAPID,the RAPID may correspond to an MCS level. Therefore, for example, oncethe UE determines an MCS level suitable for a PUSCH transmission, the UEmay select an RAPID associated with the MCS level.

3.3.2. MCS Level Related to DM-RS for MsgA PUSCH

According to various embodiments of the present disclosure, whenmultiple sets of DMRS frequency resources are allowed, it may be definedthat each DMRS frequency resource is associated with an MCS level.

For example, given two different PUSCH resources (PUSCH resource sets)(e.g., a first larger frequency resource (set) for a lower MCS level anda second smaller frequency resource (set) for a higher MCS level), thetwo different frequency resource sets may be designated for each PUSCHresource.

Embodiment

FIG. 24 is a diagram illustrating a resource configuration for MsgAaccording to various embodiments of the present disclosure.

More specifically, FIG. 24 illustrates an example of a PUSCH resourceconfiguration for a PUSCH included in MsgA and a DMRS resourceconfiguration for the PUSCH.

Referring to FIG. 24, for example, when a relatively high MCS level isused for a PUSCH included in MsgA, a relatively small frequency resourceincluding one RB may be used for the PUSCH included in MsgA. That is,for example, when a relatively high MCS level is used for the PUSCHincluded in MsgA, the PUSCH included in MsgA may be allocated to arelatively small frequency resource including one RB.

For example, when a relatively low MCS level is used for the PUSCHincluded in MsgA, a relatively large frequency resource including twoRBs may be used for the PUSCH included in MsgA. That is, for example,when a relatively low MCS level is used for the PUSCH included in theMsgA, the PUSCH included in MsgA may be allocated to a relatively largefrequency resource including two RBs.

For example, a 1^(st) comb including a set of even-numbered REs and a2^(nd) comb including a set of odd-numbered REs may be configured.

For example, when a relatively high MCS level is used for the PUSCHincluded in MsgA, the DMRS may be allocated to the 1^(st) comb.

For example, when a relatively low MCS level is used for the PUSCHincluded in MsgA, the DMRS may be allocated to the 2^(nd) comb.

That is, for example, a DMRS resource (e.g., DMRS port) may bedetermined for the PUSCH included in MsgA according to an MCS level.

Alternatively, in the case of multiple PUSCH configurations withoverlapped DMRS symbols, the BS (and/or the network) may allocate adifferent CDM group to each MsgA PUSCH configuration.

3.3.3. MCS and Payload Size

According to various embodiments of the present disclosure, a differentPUSCH resource may be available according to an MCS and/or a payloadsize.

For example, to achieve the same decoding performance regardless ofpayload, more time resources may be required for a transmission ofrelatively many bits (particularly, when there is a limitation on thetransmission power of the UE as in UL). For example, if a payload sizeis 56 bits or 72 bits, more time resources may be required fortransmission of 72 bits than for transmission of 56 bits.

For example, the corresponding resources may be allocated in timedivision.

For example, the corresponding resources may be mapped according to anRO and/or an SSB-to-RO mapping period and/or a specific period.

For example, when the UE selects a specific MCS and/or specific payloadand/or a specific PUSCH resource, the UE may select an RO inconsideration of mapping in time division and use an MsgA PUSCH resourcecorresponding to the RO.

3.4. RO Mapping for 2-Step RACH

In the 2-step RACH procedure, when MsgA (PARCH preamble+PUSCH) isconfigured, there is a need for determining an RACHtransmission/reception time and/or a PUSCH transmission/reception time.Accordingly, the PRACH preamble and the PUSCH need to be multiplexed.

Various embodiments of the present disclosure may relate to an RO (orPRACH occasion) to PUSCH (or PUSCH occasion) mapping method to supportthe 2-step RACH procedure.

According to various embodiments of the present disclosure, an RO may beconfigured and mapped based on whether the RO is allowed to be sharedbetween the 2-step RACH and the 4-step RACH (hereinafter, referred to asRO sharing).

For example, when RO sharing is allowed, PRACH preambles may beseparately configured/designated for the 4-step RACH procedure and the2-step RACH procedure. For example, when there are 64 PRACH preambles,the former 32 PRACH preambles may be configured/designated as PRACHpreambles for the 4-step RACH procedure, and the latter 32 PRACHpreambles may be configured/designated as PRACH preambles for the 2-stepRACH procedure. For example, the configuration/designation may be basedon an RACH configuration included in SIB1 and/or UE-specific RRCsignaling.

For example, the PRACH preambles may be understood as code-domainresources and identified by CPs. For example, upon receipt of a PRACHpreamble, the BS may determine whether the PRACH preamble is for the4-step RACH and/or the 2-step RACH and thus identify whether the UEtransmitting the PRACH preamble has initiated the 2-step RACH procedureand/or the 4-step RACH procedure.

On the contrary, for example, when RO sharing is not allowed (ROseparation), ROs are distinguished for the 4-step RACH procedure and the2-step RACH procedure, and thus the BS may identify whether the UEtransmitting the PRACH preamble has initiated the 2-step RACH procedureand/or the 4-step RACH procedure, based on a corresponding RO.

For example, when RO sharing is allowed between the 2-step RACH and the4-step RACH, one of the remaining PRACH preambles other than a PRACHpreamble for the 4-step RACH may be configured as a (contention-based)PRACH preamble for the 2-step RACH in an RO for the (contention-based)4-step RACH. For example, the purpose of transmitting a correspondingPRACH preamble (e.g., the 2-step RACH or the 4-step RACH) may beidentified by the BS. That is, in the above-described example, since oneof the remaining PRACH preambles other than the PRACH preamble for the4-step RACH is configured as the PRACH preamble for the 2-step RACH, theBS may identify whether the PRACH preamble transmitted by the UE is forthe 2-step RACH or for the 4-step RACH based on the corresponding PRACHpreamble.

For example, when RO sharing is allowed between the 2-step RACH and the4-step RACH, a PUSCH (or PUSCH occasion) of MsgA may be allocated in aPUSCH slot following an RACH slot.

For example, when RO sharing is not allowed between the 2-step RACH andthe 4-step RACH, an RO may be configured for the (contention-based)2-step RACH.

For example, one or more of the following two schemes, methods, oralternatives may be applied to an RO configuration for the 2-step RACH:

(1) First Method—Slot Level TDM

For example, an RO for MsgA and a PUSCH (or PUSCH occasion) for MsgA maybe multiplexed at the slot level.

For example, an RACH configuration table configured for the 4-step RACHmay be reused.

For example, the RACH configuration table may be given as Table 12 toTable 16. Table 16 to Table 20 may illustrate examples of an RACHconfiguration table for an NR frequency band FR1 and an unpairedspectrum.

TABLE 16 N^(RAslot)

, number of time- Number domain of PRACH PRACH occasions PRACH slotswithin a N^(RA)

, Configuration Preamble

_(SFN)modx = y Starting within a PRACH PRACH Index format x y Subframenumber symbol subframe slot duration 0 0 16 1 9 0 — — 0 1 0 8 1 9 0 — —0 2 0 4 1 9 0 — — 0 3 0 2 0 9 0 — — 0 4 0 2 1 9 0 — — 0 5 0 2 0 4 0 — —0 6 0 2 1 4 0 — — 0 7 0 1 0 9 0 — — 0 8 0 1 0 8 0 — — 0 9 0 1 0 7 0 — —0 10 0 1 0 6 0 — — 0 11 0 1 0 5 0 — — 0 12 0 1 0 4 0 — — 0 13 0 1 0 3 0— — 0 14 0 1 0 2 0 — — 0 15 0 1 0 1, 6 0 — — 0 16 0 1 0 1, 6 7 — — 0 170 1 0 4, 9 0 — — 0 18 0 1 0 3, 8 0 — — 0 19 0 1 0 2, 7 0 — — 0 20 0 1 08, 9 0 — — 0 21 0 1 0 4,8,9 0 — — 0 22 0 1 0 3, 4, 9 0 — — 0 23 0 1 0 7,8, 9 0 — — 0 24 0 1 0 3, 4, 8, 9 0 — — 0 25 0 1 0 6, 7, 8, 9 0 — — 0 260 1 0 1, 4, 6, 9 0 — — 0 27 0 1 0 1, 3, 5, 7, 9 0 — — 0 28 1 16 1 7 0 —— 0 29 1 8 1 7 0 — — 0 30 1 4 1 7 0 — — 0 31 1 2 0 7 0 — — 0 32 1 2 1 70 — — 0 33 1 1 0 7 0 — — 0 34 2 16 1 6 0 — — 0 35 2 8 1 6 0 — — 0 36 2 41 6 0 — — 0 37 2 2 0 6 7 — — 0 38 2 2 1 6 7 — — 0 39 2 1 0 6 7 — — 0 403 16 1 9 0 — — 0 41 3 8 1 9 0 — — 0 42 3 4 1 9 0 — — 0 43 3 2 0 9 0 — —0 44 3 2 1 9 0 — — 0 45 3 2 0 4 0 — — 0 46 3 2 1 4 0 — — 0 47 3 1 0 9 0— — 0 48 3 1 0 8 0 — — 0 49 3 1 0 7 0 — — 0 50 3 1 0 6 0 — — 0 51 3 1 05 0 — — 0 52 3 1 0 4 0 — — 0 53 3 1 0 3 0 — — 0 54 3 1 0 2 0 — — 0 55 31 0 1, 6 0 — — 0

indicates data missing or illegible when filed

TABLE 17 56 3 1 0 1, 6 7 — — 0 57 3 1 0 4, 9 0 — — 0 58 3 1 0 3, 8 0 — —0 59 3 1 0 2, 7 0 — — 0 60 3 1 0 8, 9 0 — — 0 61 3 1 0 4, 8, 9 0 — — 062 3 1 0 3, 4, 9 0 — — 0 63 3 1 0 7, 8, 9 0 — — 0 64 3 1 0 3, 4, 8, 9 0— — 0 65 3 1 0 1, 4, 6, 9 0 — — 0 66 3 1 0 1, 3, 5, 7, 9 0 — — 0 67 A116 1 9 0 2 6 2 68 A1 8 1 9 0 2 6 2 69 A1 4 1 9 0 1 6 2 70 A1 2 1 9 0 1 62 71 A1 2 1 4, 9 7 1 3 2 72 A1 2 1 7, 9 7 1 3 2 73 A1 2 1 7, 9 0 1 6 274 A1 2 1 8, 9 0 2 6 2 75 A1 2 1 4, 9 0 2 6 2 76 A1 2 1 2, 3, 4, 7, 8, 90 1 6 2 77 A1 1 0 9 0 2 6 2 78 A1 1 0 9 7 1 3 2 79 A1 1 0 9 0 1 6 2 80A1 1 0 8, 9 0 2 6 2 81 A1 1 0 4, 9 0 1 6 2 82 A1 1 0 7, 9 7 1 3 2 83 A11 0 3, 4, 8, 9 0 1 6 2 84 A1 1 0 3, 4, 8, 9 0 2 6 2 85 A1 1 0 1, 3, 5,7, 9 0 1 6 2 86 A1 1 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 7 1 3 2 87 A2 16 1 90 2 3 4 88 A2 8 1 9 0 2 3 4 89 A2 4 1 9 0 1 3 4 90 A2 2 1 7, 9 0 1 3 491 A2 2 1 8, 9 0 2 3 4 92 A2 2 1 7, 9 9 1 1 4 93 A2 2 1 4, 9 9 1 1 4 94A2 2 1 4, 9 0 2 3 4 95 A2 2 1 2, 3, 4, 7, 8, 9 0 1 3 4 96 A2 1 0 2 0 1 34 97 A2 1 0 7 0 1 3 4 98 A2 2 1 9 0 1 3 4 99 A2 1 0 9 0 2 3 4 100 A2 1 09 9 1 1 4 101 A2 1 0 9 0 1 3 4 102 A2 1 0 2, 7 0 1 3 4 103 A2 1 0 8, 9 02 3 4 104 A2 1 0 4, 9 0 1 3 4 105 A2 1 0 7, 9 9 1 1 4 106 A2 1 0 3, 4,8, 9 0 1 3 4 107 A2 1 0 3, 4, 8, 9 0 2 3 4 108 A2 1 0 1, 3, 5, 7, 9 0 13 4 109 A2 1 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 9 1 1 4 110 A3 16 1 9 0 2 26 111 A3 8 1 9 0 2 2 6 112 A3 4 1 9 0 1 2 6 113 A3 2 1 4, 9 7 1 1 6 114A3 2 1 7, 9 7 1 1 6 115 A3 2 1 7, 9 0 1 2 6 116 A3 2 1 4, 9 0 2 2 6 117A3 2 1 8, 9 0 2 2 6 118 A3 2 1 2, 3, 4, 7, 8, 9 0 1 2 6 119 A3 1 0 2 0 12 6 120 A3 1 0 7 0 1 2 6

TABLE 18 121 A3 2 1 9 0 1 2 6 122 A3 1 0 9 0 2 2 6 123 A3 1 0 9 7 1 1 6124 A3 1 0 9 0 1 2 6 125 A3 1 0 2, 7 0 1 2 6 126 A3 1 0 8, 9 0 2 2 6 127A3 1 0 4, 9 0 1 2 6 128 A3 1 0 7, 9 7 1 1 6 129 A3 1 0 3, 4, 8, 9 0 1 26 130 A3 1 0 3, 4, 8, 9 0 2 2 6 131 A3 1 0 1, 3, 5, 7, 9 0 1 2 6 132 A31 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 7 1 1 6 133 B1 4 1 9 2 1 6 2 134 B1 2 19 2 1 6 2 135 B1 2 1 7, 9 2 1 6 2 136 B1 2 1 4, 9 8 1 3 2 137 B1 2 1 4,9 2 2 6 2 138 B1 1 0 9 2 2 6 2 139 B1 1 0 9 8 1 3 2 140 B1 1 0 9 2 1 6 2141 B1 1 0 8, 9 2 2 6 2 142 B1 1 0 4, 9 2 1 6 2 143 B1 1 0 7, 9 8 1 3 2144 B1 1 0 1, 3, 5, 7, 9 2 1 6 2 145 B4 16 1 9 0 2 1 12 148 B4 8 1 9 0 21 12 147 B4 4 1 9 2 1 1 12 148 B4 2 1 9 0 1 1 12 149 B4 2 1 9 2 1 1 12150 B4 2 1 7, 9 2 1 1 12 151 B4 2 1 4, 9 2 1 1 12 152 B4 2 1 4, 9 0 2 112 153 B4 2 1 8, 9 0 2 1 12 154 B4 2 1 2, 3, 4, 7, 8, 9 0 1 1 12 155 B41 0 1 0 1 1 12 156 B4 1 0 2 0 1 1 12 157 B4 1 0 4 0 1 1 12 158 B4 1 0 70 1 1 12 159 B4 1 0 9 0 1 1 12 160 B4 1 0 9 2 1 1 12 161 B4 1 0 9 0 2 112 162 B4 1 0 4, 9 2 1 1 12 163 B4 1 0 7, 9 2 1 1 12 164 B4 1 0 8, 9 0 21 12 165 B4 1 0 3, 4, 8, 9 2 1 1 12 166 B4 1 0 1, 3, 5, 7, 9 2 1 1 12167 B4 1 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 0 2 1 12 168 B4 1 0 0, 1, 2, 3,4, 5, 6, 7, 8, 9 2 1 1 12 169 C0 16 1 9 2 2 6 2 170 C0 8 1 9 2 2 6 2 171C0 4 1 9 2 1 6 2 172 C0 2 1 9 2 1 6 2 173 C0 2 1 8, 9 2 2 6 2 174 C0 2 17, 9 2 1 6 2 175 C0 2 1 7, 9 8 1 6 2 176 C0 2 1 4, 9 8 1 6 2 177 C0 2 14, 9 2 2 6 2 178 C0 2 1 2, 3, 4, 7, 8, 9 2 1 6 2 179 C0 1 0 9 2 2 6 2180 C0 1 0 9 8 1 6 2 181 C0 1 0 9 2 1 6 2 182 C0 1 0 8, 9 2 2 6 2 183 C01 0 4, 9 2 1 6 2 184 C0 1 0 7, 9 8 1 6 2 185 C0 1 0 3, 4, 8, 9 2 1 6 2

TABLE 19 186 C0 1 0 3, 4, 8, 9 2 2 6 2 187 C0 1 0 1, 3, 5, 7, 9 2 1 6 2188 C0 1 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 8 1 3 2 189 C2 16 1 9 2 2 2 6190 C2 8 1 9 2 2 2 6 191 C2 4 1 9 2 1 2 6 192 C2 2 1 9 2 1 2 6 193 C2 21 8, 9 2 2 2 6 194 C2 2 1 7, 9 2 1 2 6 195 C2 2 1 7, 9 8 1 1 6 196 C2 21 4, 9 8 1 1 6 197 C2 2 1 4,9 2 2 2 6 198 C2 2 1 2, 3, 4, 7, 8, 9 2 1 26 199 C2 8 1 9 8 2 1 6 200 C2 4 1 9 8 1 1 6 201 C2 1 0 9 2 2 2 6 202 C21 0 9 8 1 1 6 203 C2 1 0 9 2 1 2 6 204 C2 1 0 8, 9 2 2 2 6 205 C2 1 0 4,9 2 1 2 6 206 C2 1 0 7, 9 8 1 1 6 207 C2 1 0 3, 4, 8, 9 2 1 2 6 208 C2 10 3, 4, 8, 9 2 2 2 6 209 C2 1 0 1, 3, 5, 7, 9 2 1 2 6 210 C2 1 0 0, 1,2, 3, 4, 5, 6, 7, 8, 9 8 1 1 6 211 A1/B1 2 1 9 2 1 6 2 212 A1/B1 2 1 4,9 8 1 3 2 213 A1/B1 2 1 7, 9 8 1 3 2 214 A1/B1 2 1 7, 9 2 1 6 2 215A1/B1 2 1 4, 9 2 2 6 2 216 A1/B1 2 1 8. 9 2 2 6 2 217 A1/B1 1 0 9 2 2 62 218 A1/B1 1 0 9 8 1 3 2 219 A1/B1 1 0 9 2 1 6 2 220 A1/B1 1 0 8, 9 2 26 2 221 A1/B1 1 0 4, 9 2 1 6 2 222 A1/B1 1 0 7, 9 8 1 3 2 223 A1/B1 1 03, 4, 8, 9 2 2 6 2 224 A1/B1 1 0 1, 3, 5, 7, 9 2 1 6 2 225 A1/B1 1 0 0,1, 2, 3, 4, 5, 6, 7, 8, 9 8 1 3 2 226 A2/B2 2 1 9 0 1 3 4 227 A2/B2 2 14, 9 6 1 2 4 228 A2/B2 2 1 7, 9 6 1 2 4 229 A2/B2 2 1 4, 9 0 2 3 4 230A2/B2 2 1 8, 9 0 2 3 4 231 A2/B2 1 0 9 0 2 3 4 232 A2/B2 1 0 9 6 1 2 4233 A2/B2 1 0 9 0 1 3 4 234 A2/B2 1 0 8, 9 0 2 3 4 235 A2/B2 1 0 4, 9 01 3 4 236 A2/B2 1 0 7,9 6 1 3 4 237 A2/B2 1 0 3, 4, 8, 9 0 1 3 4 238A2/B2 1 0 3, 4, 8, 9 0 2 3 4 239 A2/B2 1 0 1, 3, 5, 7, 9 0 1 3 4 240A2/B2 1 0 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 6 1 2 4 241 A3/B3 2 1 9 0 1 2 6242 A3/B3 2 1 4, 9 2 1 2 6 243 A3/B3 2 1 7, 9 0 1 2 6 244 A3/B3 2 1 7, 92 1 2 6 245 A3/B3 2 1 4, 9 0 2 2 6 246 A3/B3 2 1 8, 9 0 2 2 6 247 A3/B31 0 9 0 2 2 6 248 A3/B3 1 0 9 2 1 2 6 249 A3/B3 1 0 9 0 1 2 6 250 A3/B31 0 8, 9 0 2 2 6

TABLE 20 251 A3/B3 1 0 4, 9 0 1 2 6 252 A3/B3 1 0 7, 9 2 1 2 6 253 A3/B31 0 3, 4, 8, 9 0 2 2 6 254 A3/B3 1 0 1, 3, 5, 7, 9 0 1 2 6 255 A3/B3 1 00, 1, 2, 3, 4, 5, 6, 7, 8, 9 2 1 2 6 256 0 16 1 7 0 — — 0 257 0 8 1 7 0— — 0 258 0 4 1 7 0 — — 0 259 0 2 0 7 0 — — 0 260 0 2 1 7 0 —   0 261 02 0 2 0 — — 0 262 0 2 1 2 0 — — 0

For example, the RACH configuration table may be designed on theassumption that most of the OFDM symbols of an RACH slot or a 2^(nd)RACH half-slot are used for an RO.

Accordingly, in this case, for example, the RO and the PUSCH (or PUSCHoccasion) may be multiplexed in different slots.

FIGS. 25A to 25D are diagrams illustrating exemplary MsgA configurationsaccording to various embodiments of the present disclosure.

More specifically, FIGS. 25A to 25D are diagrams illustrating examplesof the first method of multiplexing an RO for MsgA and a PUSCH (or PUSCHoccasion) for MsgA at the slot level.

Referring to FIGS. 25A to 25D, an RO for transmitting a PRACH preambleincluded in MsgA and a PUSCH occasion for transmitting a PUSCH includedin Msg A may be multiplexed in TDM at the slot level.

For example, the RO may be included or mapped in an RACH slot locatedearlier than a PUSCH slot on the time domain. For example, the PUSCHoccasion may be included or mapped in the PUSCH slot located after theRACH slot in the time domain.

For example, ROs and/or PUSCH occasions may be multiplexed in each slotin various manners.

For example, FIG. 25A illustrates an example in which ROs aremultiplexed in TDM in an RACH slot and PUSCHs are multiplexed in FDM andTDM in a PUSCH slot.

For example, FIG. 25B illustrates an example in which ROs aremultiplexed in FDM and TDM in an RACH slot and PUSCHs are multiplexed inFDM in a PUSCH slot.

For example, FIG. 25C illustrates an example in which ROs aremultiplexed in FDM in an RACH slot and PUSCHs are multiplexed in TDM ina PUSCH slot.

For example, FIG. 25D illustrates an example in which ROs aremultiplexed in TDM in an RACH slot and PUSCHs are multiplexed in TDM andCDM in a PUSCH slot.

For example, a certain time offset may be configured between the ROs andthe PUSCH occasions in the time domain. That is, for example, a certaintime offset may be configured between the RACH slot including the ROsand the PUSCH slot including the PUSCH occasions in the time domain.

For example, the time offset may include a predetermined number ofslots.

On the contrary, when a time offset is not configured, the RACH slot andthe PUSCH slot may be contiguous in the time domain.

(1) Second Method-Symbol Level TDM

For example, an RO for MsgA and a PUSCH (or PUSCH occasion) for MsgA maybe multiplexed at the symbol level.

For example, a configuration of using OFDM symbols of a 1st RACHhalf-slot (in a slot for MsgA) as an RO may be considered.

For example, a PUSCH (or PUSCH occasion) for MsgA may be allocated inOFDM symbols after RO OFDM symbols (in the slot).

FIGS. 26A to 26D are diagrams illustrating exemplary MsgA configurationsaccording to various embodiments of the present disclosure.

More specifically, FIGS. 26A to 26D are diagrams illustrating examplesof the second method of multiplexing an RO for MsgA and a PUSCH (orPUSCH occasion) for MsgA at the symbol level.

Referring to FIGS. 26A to 26D, an RO for transmitting a PRACH preambleincluded in MsgA and a PUSCH occasion for transmitting a PUSCH includedin Msg A may be multiplexed in TDM at the symbol level.

For example, the RO and the PUSCH occasion may be included in one slot.

For example, the RO may be included or mapped in an RACH half-slotlocated earlier than a PUSCH half-slot in the time domain. For example,the PUSCH occasion may be included or mapped in the PUSCH half-slotlocated after the RACH half-slot in the time domain.

For example, the RO may be included or mapped in one or more OFDMsymbols of the RACH half-slot. For example, the PUSCH occasion may beincluded or mapped in one or more OFDM symbols of the PUSCH half-slot.

For example, ROs and/or PUSCH occasions may be multiplexed in eachhalf-slot in various manners.

For example, FIG. 26A illustrates an example in which one RO isconfigured in an RACH half-slot, and PUSCHs are multiplexed in FDM in aPUSCH half-slot.

For example, FIG. 26B illustrates an example in which ROs aremultiplexed in FDM in an RACH half-slot and PUSCHs are multiplexed inTDM in a PUSCH half-slot.

For example, FIG. 26C illustrates an example in which ROs aremultiplexed in TDM in an RACH half-slot and PUSCHs are multiplexed inFDM and TDM in a PUSCH half-slot.

For example, FIG. 26D illustrates an example in which ROs aremultiplexed in FDM and TDM in an RACH half-slot and PUSCHs aremultiplexed in TDM and CDM in a PUSCH half-slot.

In summary, according to various embodiments of the present disclosure,an RO may be configured or mapped based on whether RO sharing is allowedbetween the 2-step RACH and the 4-step RACH.

For example, when RO sharing is allowed, one of the remaining PRACHpreambles other than a PRACH preamble for the 4-step RACH may beconfigured as a PRACH preamble for the 2-step RACH.

For example, when RO sharing is not allowed, one or more of thefollowing two schemes or methods or alternatives may be applied:

(1) First Method—Slot Level TDM

For example, an RACH configuration table configured for the 4-step RACHmay be reused. For example, an RO for MsgA and a PUSCH (or PUSCHoccasion) for MsgA may be multiplexed at the slot level.

(1) Second Method—Symbol Level TDM

For example, a configuration of using OFDM symbols of a first RACHhalf-slot (of a slot for MsgA) as an RO may be considered. For example,an RO for MsgA and a PUSCH (or PUSCH occasion) for MsgA may bemultiplexed at the symbol level.

Since examples of the above-described proposal method may also beincluded in one of implementation methods of the various embodiments ofthe present disclosure, it is obvious that the examples are regarded asa sort of proposed methods. Although the above-proposed methods may beindependently implemented, the proposed methods may be implemented in acombined (aggregated) form of a part of the proposed methods. A rule maybe defined such that the BS informs the UE of information as to whetherthe proposed methods are applied (or information about rules of theproposed methods) through a predefined signal (e.g., a physical layersignal or a higher-layer signal).

3.5. Initial Network Access and Communication Process

According to various embodiments of the present disclosure, a UE mayperform a network access process to perform the above-described/proposedprocedures and/or methods. For example, the UE may receive systeminformation and configuration information required to perform theabove-described/proposed procedures and/or methods and store thereceived information in a memory. The configuration information requiredfor various embodiments of the present disclosure may be received byhigher-layer signaling (e.g., RRC signaling or MAC signaling).

FIG. 27 is a diagram illustrating an initial network access andsubsequent communication process. In an NR system to which variousembodiments of the present disclosure are applicable, a physical channeland an RS may be transmitted by beamforming. When beamforming-basedsignal transmission is supported, beam management may be performed forbeam alignment between a BS and a UE. Further, a signal proposed invarious embodiments of the present disclosure may betransmitted/received by beamforming. In RRC_IDLE mode, beam alignmentmay be performed based on a synchronization signal block (SSB or SS/PBCHblock), whereas in RRC_CONNECTED mode, beam alignment may be performedbased on a CSI-RS (in DL) and an SRS (in UL). On the contrary, whenbeamforming-based signal transmission is not supported, beam-relatedoperations may be omitted in the following description.

Referring to FIG. 27, a BS (e.g., eNB) may periodically transmit an SSB(S2702). The SSB includes a PSS/SSS/PBCH. The SSB may be transmitted bybeam sweeping. The BS may then transmit remaining minimum systeminformation (RMSI) and other system information (OSI) (S2704). The RMSImay include information required for the UE to perform initial access tothe BS (e.g., PRACH configuration information). After detecting SSBs,the UE identifies the best SSB. The UE may then transmit an RACHpreamble (Message 1; Msg1) in PRACH resources linked/corresponding tothe index (i.e., beam) of the best SSB (S2706). The beam direction ofthe RACH preamble is associated with the PRACH resources. Associationbetween PRACH resources (and/or RACH preambles) and SSBs (SSB indexes)may be configured by system information (e.g., RMSI). Subsequently, inan RACH procedure, the BS may transmit a random access response (RAR)(Msg2) in response to the RACH preamble (S2708), the UE may transmitMsg3 (e.g., RRC Connection Request) based on a UL grant included in theRAR (S2710), and the BS may transmit a contention resolution message(Msg4) (S2712). Msg4 may include RRC Connection Setup.

When an RRC connection is established between the BS and the UE in theRACH procedure, beam alignment may subsequently be performed based on anSSB/CSI-RS (in DL) and an SRS (in UL). For example, the UE may receivean SSB/CSI-RS (S2714). The SSB/CSI-RS may be used for the UE to generatea beam/CSI report. The BS may request the UE to transmit a beam/CSIreport, by DCI (S2716). In this case, the UE may generate a beam/CSIreport based on the SSB/CSI-RS and transmit the generated beam/CSIreport to the BS on a PUSCH/PUCCH (S2718). The beam/CSI report mayinclude a beam measurement result, information about a preferred beam,and so on. The BS and the UE may switch beams based on the beam/CSIreport (52720 a and 52720 b).

Subsequently, the UE and the BS may perform the above-described/proposedprocedures and/or methods. For example, the UE and the BS may transmit awireless signal by processing information stored in a memory or mayprocess received wireless signal and store the processed signal in thememory according to various embodiments of the present disclosure, basedon configuration information obtained in the network access process(e.g., the system information acquisition process, the RRC connectionprocess through an RACH, and so on). The wireless signal may include atleast one of a PDCCH, a PDSCH, or an RS on DL and at least one of aPUCCH, a PUSCH, or an SRS on UL.

3.6. DRX (Discontinuous Reception)

FIGS. 28A and 28B are exemplary DRX operations according to variousembodiments of the present disclosure.

According to various embodiments of the present disclosure, the UE mayperform a DRX operation in the afore-described/proposed proceduresand/or methods. When the UE is configured with DRX, the UE may reducepower consumption by receiving a DL signal discontinuously. DRX may beperformed in an RRC_IDLE state, an RRC INACTIVE state, and anRRC_CONNECTED state. In the RRC_IDLE state and the RRC INACTIVE state,DRX is used to receive a paging signal discontinuously.

3.6.1. RRC_CONNECTED DRX

In in the RRC_CONNECTED state, DRX is used to receive a PDCCHdiscontinuously. DRX in the RRC_CONNECTED state is referred to asRRC_CONNECTED DRX).

Referring to FIG. 28A, a DRX cycle includes an On Duration and anOpportunity for DRX. The DRX cycle defines a time interval betweenperiodic repetitions of the On Duration. The On Duration is a timeperiod during which the UE monitors a PDCCH. When the UE is configuredwith DRX, the UE performs PDCCH monitoring during the On Duration. Whenthe UE successfully detects a PDCCH during the PDCCH monitoring, the UEstarts an inactivity timer and is kept awake. On the contrary, when theUE fails in detecting any PDCCH during the PDCCH monitoring, the UEtransitions to a sleep state after the On Duration. Accordingly, whenDRX is configured, the UE may perform PDCCH monitoring/receptiondiscontinuously in the time domain in the afore-described proceduresand/or methods. For example, when DRX is configured, PDCCH receptionoccasions (e.g., slots with PDCCH search spaces) may be configureddiscontinuously according to a DRX configuration in the presentdisclosure. On the contrary, when DRX is not configured, the UE mayperform PDCCH monitoring/reception continuously in the time domain inthe afore-described procedures and/or methods according toimplementation(s). For example, when DRX is not configured, PDCCHreception occasions (e.g., slots with PDCCH search spaces) may beconfigured continuously in the present disclosure. Irrespective ofwhether DRX is configured, PDCCH monitoring may be restricted during atime period configured as a measurement gap.

Table 21 describes a DRX operation of a UE (in the RRC_CONNECTED state).Referring to Table 21, DRX configuration information is received byhigher-layer signaling (e.g., RRC signaling), and DRX ON/OFF iscontrolled by a DRX command from the MAC layer. Once DRX is configured,the UE may perform PDCCH monitoring discontinuously the afore-describedprocedures and/or methods according to various embodiments of thepresent disclosure.

TABLE 21 Type of signals UE procedure 1^(st) step RRC signalling -Receive DRX configuration (MAC- information CellGroupConfig) 2^(nd) stepMAC CE - Receive DRX command ((Long) DRX command MAC CE) 3^(rd) Step — -Monitor a PDCCH during an on-duration of a DRX cycle

MAC-CellGroupConfig includes configuration information required toconfigure MAC parameters for a cell group. MAC-CellGroupConfig may alsoinclude DRX configuration information. For example, MAC-CellGroupConfigmay include the following information in defining DRX.

-   -   Value of drx-OnDurationTimer: defines the duration of the        starting period of the DRX cycle.    -   Value of drx-InactivityTimer: defines the duration of a time        period during which the UE is awake after a PDCCH occasion in        which a PDCCH indicating initial UL or DL data has been        detected.    -   Value of drx-HARQ-RTT-TimerDL: defines the duration of a maximum        time period until a DL retransmission is received after        reception of a DL initial transmission.    -   Value of drx-HARQ-RTT-TimerDL: defines the duration of a maximum        time period until a grant for a UL retransmission is received        after reception of a grant for a UL initial transmission.    -   drx-LongCycleStartOffset: defines the duration and starting time        of a DRX cycle.    -   drx-ShortCycle (optional): defines the duration of a short DRX        cycle.

When any of drx-OnDurationTimer, drx-InactivityTimer,drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is running, the UEperforms PDCCH monitoring in each PDCCH occasion, staying in the awakestate.

3.6.2. RRC_IDLE DRX

In the RRC_IDLE state and the RRC INACTIVE state, DRX is used to receivea paging signal discontinuously. For convenience, DRX performed in theRRC_IDLE (or RRC INACTIVE) state is referred to as RRC_IDLE DRX.

Therefore, when DRX is configured, PDCCH monitoring/reception may beperformed discontinuously in the time domain in theafore-described/proposed procedures and/or methods.

Referring to FIG. 28B, DRX may be configured for discontinuous receptionof a paging signal. The UE may receive DRX configuration informationfrom the BS by higher-layer (e.g., RRC) signaling. The DRX configurationinformation may include a DRX cycle, a DRX offset, configurationinformation for a DRX timer, and the like. The UE repeats an On Durationand a Sleep duration according to a DRX cycle. The UE may operate in awakeup mode during the On duration and in a sleep mode during the Sleepduration. In the wakeup mode, the UE may monitor a paging occasion (PO)to receive a paging message. A PO means a time resource/interval (e.g.,subframe or slot) in which the UE expects to receive a paging message.PO monitoring includes monitoring a PDCCH (MPDCCH or NPDCCH) scrambledwith a P-RNTI (hereinafter, referred to as a paging PDCCH) in a PO. Thepaging message may be included in the paging PDCCH or in a PDSCHscheduled by the paging PDCCH. One or more POs may be included in apaging frame (PF), and the PF may be periodically configured based on aUE ID. A PF may correspond to one radio frame, and the UE ID may bedetermined based on the International Mobile Subscriber Identity (IMSI)of the UE. When DRX is configured, the UE monitors only one PO per DRXcycle. When the UE receives a paging message indicating a change of itsID and/or system information in a PO, the UE may perform an RACHprocedure to initialize (or reconfigure) a connection with the BS, orreceive (or obtain) new system information from the BS. Therefore, POmonitoring may be performed discontinuously in the time domain toperform an RACH procedure for connection to the BS or to receive (orobtain) new system information from the BS in the afore-describedprocedures and/or methods.

Those skilled in the art will understand clearly that above-describedinitial access process and/or DRX operation may be combined with thecontents of clause 1 to clause 3 described before to constitute othervarious embodiments of the present disclosure.

FIG. 29 is a simplified diagram illustrating a method of operating a UEand a BS according to various embodiments of the present disclosure.

FIG. 30 is a flowchart illustrating a method of operating a UE accordingto various embodiments of the present disclosure.

FIG. 31 is a flowchart illustrating a method of operating a BS accordingto various embodiments of the present disclosure.

Referring to FIGS. 29 to 31, the UE may obtain/generate MsgA including aPRACH preamble and a PUSCH in operations 2701 and 2801 according to anexemplary embodiment.

In an exemplary embodiment, MsgA may be related to a random accessprocedure.

In operations 2703, 2803, and 2903 according to an exemplary embodiment,the UE may transmit MsgA, and the BS may receive MsgA.

In operations 2705 and 2905 according to an exemplary embodiment, the BSmay obtain the PRACH preamble and the PUSCH included in MsgA.

In operations 2707, 2807, and 2907 according to an exemplary embodiment,the BS may transmit MsgB, and the UE may receive MsgB. In an exemplaryembodiment, MsgB may be related to the random access procedure.

In an exemplary embodiment, the PUSCH may be transmitted and received inat least one of consecutive PUSCH occasions in the frequency domain andthe time domain.

In an exemplary embodiment, the PRACH preamble may be obtained fromamong at least one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

A more specific operation of the BS and/or the UE according to theabove-described various embodiments of the present disclosure may bedescribed and performed based on the afore-described clause 1 to clause3.

Since examples of the above-described proposal method may also beincluded in one of implementation methods of the various embodiments ofthe present disclosure, it is obvious that the examples are regarded asa sort of proposed methods. Although the above-proposed methods may beindependently implemented, the proposed methods may be implemented in acombined (aggregated) form of a part of the proposed methods. A rule maybe defined such that the BS informs the UE of information as to whetherthe proposed methods are applied (or information about rules of theproposed methods) through a predefined signal (e.g., a physical layersignal or a higher-layer signal).

4. Exemplary Configurations of Devices Implementing Various Embodimentsof the Present Disclosure

4.1. Exemplary Configurations of Devices to which Various Embodiments ofthe Present Disclosure are Applied

FIG. 32 is a diagram illustrating devices that implement variousembodiments of the present disclosure.

The devices illustrated in FIG. 32 may be a UE and/or a BS (e.g., eNB orgNB) adapted to perform the afore-described mechanisms, or any devicesperforming the same operation.

Referring to FIG. 32, the device may include a digital signal processor(DSP)/microprocessor 210 and a radio frequency (RF) module (transceiver)235. The DSP/microprocessor 210 is electrically coupled to thetransceiver 235 and controls the transceiver 235. The device may furtherinclude a power management module 205, a battery 255, a display 215, akeypad 220, a SIM card 225, a memory device 230, an antenna 240, aspeaker 245, and an input device 250, depending on a designer'sselection.

Particularly, FIG. 32 may illustrate a UE including a receiver 235configured to receive a request message from a network and a transmitter235 configured to transmit timing transmission/reception timinginformation to the network. These receiver and transmitter may form thetransceiver 235. The UE may further include a processor 210 coupled tothe transceiver 235.

Further, FIG. 32 may illustrate a network device including a transmitter235 configured to transmit a request message to a UE and a receiver 235configured to receive timing transmission/reception timing informationfrom the UE. These transmitter and receiver may form the transceiver235. The network may further include the processor 210 coupled to thetransceiver 235. The processor 210 may calculate latency based on thetransmission/reception timing information.

A processor included in a UE (or a communication device included in theUE) and a BE (or a communication device included in the BS) according tovarious embodiments of the present disclosure may operate as follows,while controlling a memory.

According to various embodiments of the present disclosure, a UE or a BSmay include at least one transceiver, at least one memory, and at leastone processor coupled to the at least one transceiver and the at leastone memory. The at least one memory may store instructions causing theat least one processor to perform the following operations.

A communication device included in the UE or the BS may be configured toinclude the at least one processor and the at least one memory. Thecommunication device may be configured to include the at least onetransceiver, or may be configured not to include the at least onetransceiver but to be connected to the at least one transceiver.

According to various embodiments of the present disclosure, at least oneprocessor included in a UE (or at least one processor of a communicationdevice included in the UE) may obtain MsgA including a PRACH preambleand a PUSCH.

According to various embodiments of the present disclosure, the at leastone processor included in the UE may transmit MsgA.

In an exemplary embodiment, MsgA may be related to a random accessprocedure.

According to various embodiments of the present disclosure, the at leastone processor included in the UE may receive MsgB.

In an exemplary embodiment, MsgB may be related to the random accessprocedure.

In an exemplary embodiment, the PUSCH may be transmitted in at least oneof consecutive PUSCH occasions in the frequency domain and the timedomain.

In an exemplary embodiment, the PRACH preamble may be obtained fromamong at least one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

According to various embodiments of the present disclosure, at least oneprocessor included in a BS (or at least one processor of a communicationdevice included in the BS) may receive MsgA including a PRACH preambleand a PUSCH.

According to various embodiments of the present disclosure, the at leastone processor included in the BS may obtain the PRACH preamble and thePUSCH included in MsgA.

In an exemplary embodiment, MsgA may be related to a random accessprocedure.

According to various embodiments of the present disclosure, the at leastone processor included in the BS may transmit MsgB.

In an exemplary embodiment, MsgB may be related to the random accessprocedure.

In an exemplary embodiment, the PUSCH may be received in at least one ofconsecutive PUSCH occasions in the frequency domain and the time domain.

In an exemplary embodiment, the PRACH preamble may be obtained fromamong at least one preconfigured PRACH preamble.

In an exemplary embodiment, the PUSCH may include a DMRS.

In an exemplary embodiment, the DMRS may be related to (i) at least oneDMRS port and (ii) at least one DMRS sequence.

In an exemplary embodiment, the at least one preconfigured PRACHpreamble may be mapped to (i) the at least one DMRS port and (ii) the atleast one DMRS sequence based on (i) an index of each of the at leastone DMRS port and (ii) an index of each of the at least one DMRSsequence.

A more specific operation of a processor included in a BS and/or a UEaccording to various embodiments of the present disclosure may bedescribed and performed based on the afore-described clause 1 to clause3.

Unless contradicting with each other, various embodiments of the presentdisclosure may be implemented in combination. For example, the BS and/orthe UE according to various embodiments of the present disclosure mayperform operations in combination of the embodiments of theafore-described clause 1 to clause 3, unless contradicting with eachother.

4.2. Example of Communication System to which Various Embodiments of thePresent Disclosure are Applied

In the present specification, various embodiments of the presentdisclosure have been mainly described in relation to data transmissionand reception between a BS and a UE in a wireless communication system.However, various embodiments of the present disclosure are not limitedthereto. For example, various embodiments of the present disclosure mayalso relate to the following technical configurations.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the various embodiments of the presentdisclosure described in this document may be applied to, without beinglimited to, a variety of fields requiring wirelesscommunication/connection (e.g., 5G) between devices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 33 illustrates an exemplary communication system to which variousembodiments of the present disclosure are applied.

Referring to FIG. 33, a communication system 1 applied to the variousembodiments of the present disclosure includes wireless devices, BaseStations (BSs), and a network. Herein, the wireless devices representdevices performing communication using Radio Access Technology (RAT)(e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may bereferred to as communication/radio/5G devices. The wireless devices mayinclude, without being limited to, a robot 100 a, vehicles 100 b-1 and100 b-2, an eXtended Reality (XR) device 100 c, a hand-held device 100d, a home appliance 100 e, an Internet of Things (IoT) device 100 f, andan Artificial Intelligence (AI) device/server 400. For example, thevehicles may include a vehicle having a wireless communication function,an autonomous driving vehicle, and a vehicle capable of performingcommunication between vehicles. Herein, the vehicles may include anUnmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may includean Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) deviceand may be implemented in the form of a Head-Mounted Device (HMD), aHead-Up Display (HUD) mounted in a vehicle, a television, a smartphone,a computer, a wearable device, a home appliance device, a digitalsignage, a vehicle, a robot, etc. The hand-held device may include asmartphone, a smartpad, a wearable device (e.g., a smartwatch or asmartglasses), and a computer (e.g., a notebook). The home appliance mayinclude a TV, a refrigerator, and a washing machine. The IoT device mayinclude a sensor and a smartmeter. For example, the BSs and the networkmay be implemented as wireless devices and a specific wireless device200 a may operate as a BS/network node with respect to other wirelessdevices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as UL/DLcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the various embodiments ofthe present disclosure.

4.2.1 Example of Wireless Devices to which Various Embodiments of thePresent Disclosure are Applied

FIG. 34 illustrates exemplary wireless devices to which variousembodiments of the present disclosure are applicable.

Referring to FIG. 34, a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. W1.

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the various embodiments of the presentdisclosure, the wireless device may represent a communicationmodem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the various embodiments of the present disclosure, thewireless device may represent a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

According to various embodiments of the present disclosure, one or morememories (e.g., 104 or 204) may store instructions or programs which,when executed, cause one or more processors operably coupled to the oneor more memories to perform operations according to various embodimentsor implementations of the present disclosure.

According to various embodiments of the present disclosure, acomputer-readable storage medium may store one or more instructions orcomputer programs which, when executed by one or more processors, causethe one or more processors to perform operations according to variousembodiments or implementations of the present disclosure.

According to various embodiments of the present disclosure, a processingdevice or apparatus may include one or more processors and one or morecomputer memories connected to the one or more processors. The one ormore computer memories may store instructions or programs which, whenexecuted, cause the one or more processors operably coupled to the oneor more memories to perform operations according to various embodimentsor implementations of the present disclosure.

4.2.2. Example of Using Wireless Devices to which Various Embodiments ofthe Present Disclosure are Applied

FIG. 35 illustrates other exemplary wireless devices to which variousembodiments of the present disclosure are applied. The wireless devicesmay be implemented in various forms according to a use case/service (seeFIG. 33).

Referring to FIG. 35, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 33 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 and/or the one or morememories 104 and 204 of FIG. 33. For example, the transceiver(s) 114 mayinclude the one or more transceivers 106 and 206 and/or the one or moreantennas 108 and 208 of FIG. 33. The control unit 120 is electricallyconnected to the communication unit 110, the memory 130, and theadditional components 140 and controls overall operation of the wirelessdevices. For example, the control unit 120 may control anelectric/mechanical operation of the wireless device based onprograms/code/commands/information stored in the memory unit 130. Thecontrol unit 120 may transmit the information stored in the memory unit130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. W1), the vehicles (100 b-1 and 100 b-2 of FIG. W1), the XRdevice (100 c of FIG. W1), the hand-held device (100 d of FIG. W1), thehome appliance (100 e of FIG. W1), the IoT device (100 f of FIG. W1), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. W1), the BSs (200 of FIG. W1), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 35, the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 35 will be described indetail with reference to the drawings.

4.2.3. Example of Portable Device to which Various Embodiments of thePresent Disclosure are Applied

FIG. 36 illustrates an exemplary portable device to which variousembodiments of the present disclosure are applied. The portable devicemay be any of a smartphone, a smartpad, a wearable device (e.g., asmartwatch or smart glasses), and a portable computer (e.g., a laptop).A portable device may also be referred to as mobile station (MS), userterminal (UT), mobile subscriber station (MSS), subscriber station (SS),advanced mobile station (AMS), or wireless terminal (WT).

Referring to FIG. 36, a hand-held device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an I/O unit 140 c.The antenna unit 108 may be configured as a part of the communicationunit 110. Blocks 110 to 130/140 a to 140 c correspond to the blocks 110to 130/140 of FIG. X3, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an Application Processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. The memory unit 130 may store input/output data/information.The power supply unit 140 a may supply power to the hand-held device 100and include a wired/wireless charging circuit, a battery, etc. Theinterface unit 140 b may support connection of the hand-held device 100to other external devices. The interface unit 140 b may include variousports (e.g., an audio I/O port and a video I/O port) for connection withexternal devices. The I/O unit 140 c may input or output videoinformation/signals, audio information/signals, data, and/or informationinput by a user. The I/O unit 140 c may include a camera, a microphone,a user input unit, a display unit 140 d, a speaker, and/or a hapticmodule.

As an example, in the case of data communication, the I/O unit 140 c mayacquire information/signals (e.g., touch, text, voice, images, or video)input by a user and the acquired information/signals may be stored inthe memory unit 130. The communication unit 110 may convert theinformation/signals stored in the memory into radio signals and transmitthe converted radio signals to other wireless devices directly or to aBS. The communication unit 110 may receive radio signals from otherwireless devices or the BS and then restore the received radio signalsinto original information/signals. The restored information/signals maybe stored in the memory unit 130 and may be output as various types(e.g., text, voice, images, video, or haptic) through the I/O unit 140c.

4.2.4. Example of Vehicle or Autonomous Driving Vehicle to which VariousEmbodiments of the Present Disclosure.

FIG. 37 illustrates an exemplary vehicle or autonomous driving vehicleto which various embodiments of the present disclosure. The vehicle orautonomous driving vehicle may be implemented as a mobile robot, a car,a train, a manned/unmanned aerial vehicle (AV), a ship, or the like.

Referring to FIG. 37, a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. X3,respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous driving vehicle 100. The control unit 120 mayinclude an Electronic Control Unit (ECU). The driving unit 140 a maycause the vehicle or the autonomous driving vehicle 100 to drive on aroad. The driving unit 140 a may include an engine, a motor, apowertrain, a wheel, a brake, a steering device, etc. The power supplyunit 140 b may supply power to the vehicle or the autonomous drivingvehicle 100 and include a wired/wireless charging circuit, a battery,etc. The sensor unit 140 c may acquire a vehicle state, ambientenvironment information, user information, etc. The sensor unit 140 cmay include an Inertial Measurement Unit (IMU) sensor, a collisionsensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor,a heading sensor, a position module, a vehicle forward/backward sensor,a battery sensor, a fuel sensor, a tire sensor, a steering sensor, atemperature sensor, a humidity sensor, an ultrasonic sensor, anillumination sensor, a pedal position sensor, etc. The autonomousdriving unit 140 d may implement technology for maintaining a lane onwhich a vehicle is driving, technology for automatically adjustingspeed, such as adaptive cruise control, technology for autonomouslydriving along a determined path, technology for driving by automaticallysetting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous driving vehicle 100may move along the autonomous driving path according to the driving plan(e.g., speed/direction control). In the middle of autonomous driving,the communication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous driving vehicles and provide the predicted trafficinformation data to the vehicles or the autonomous driving vehicles.

4.2.5. Example of AR/VR and Vehicle to which Various Embodiments of thePresent Disclosure

FIG. 38 illustrates an exemplary vehicle to which various embodiments ofthe present disclosure are applied. The vehicle may be implemented as atransportation means, a train, an aircraft, a ship, or the like.

Referring to FIG. 38, a vehicle 100 may include a communication unit110, a control unit 120, a memory unit 130, an I/O unit 140 a, and apositioning unit 140 b. Herein, the blocks 110 to 130/140 a and 140 bcorrespond to blocks 110 to 130/140 of FIG. 35.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as other vehiclesor BSs. The control unit 120 may perform various operations bycontrolling constituent elements of the vehicle 100. The memory unit 130may store data/parameters/programs/code/commands for supporting variousfunctions of the vehicle 100. The I/O unit 140 a may output an AR/VRobject based on information within the memory unit 130. The I/O unit 140a may include an HUD. The positioning unit 140 b may acquire informationabout the position of the vehicle 100. The position information mayinclude information about an absolute position of the vehicle 100,information about the position of the vehicle 100 within a travelinglane, acceleration information, and information about the position ofthe vehicle 100 from a neighboring vehicle. The positioning unit 140 bmay include a GPS and various sensors.

As an example, the communication unit 110 of the vehicle 100 may receivemap information and traffic information from an external server andstore the received information in the memory unit 130. The positioningunit 140 b may obtain the vehicle position information through the GPSand various sensors and store the obtained information in the memoryunit 130. The control unit 120 may generate a virtual object based onthe map information, traffic information, and vehicle positioninformation and the I/O unit 140 a may display the generated virtualobject in a window in the vehicle (1410 and 1420). The control unit 120may determine whether the vehicle 100 normally drives within a travelinglane, based on the vehicle position information. If the vehicle 100abnormally exits from the traveling lane, the control unit 120 maydisplay a warning on the window in the vehicle through the I/O unit 140a. In addition, the control unit 120 may broadcast a warning messageregarding driving abnormity to neighboring vehicles through thecommunication unit 110. According to situation, the control unit 120 maytransmit the vehicle position information and the information aboutdriving/vehicle abnormality to related organizations.

In summary, various embodiments of the present disclosure may beimplemented through a certain device and/or UE.

For example, the certain device may be any of a BS, a network node, atransmitting UE, a receiving UE, a wireless device, a wirelesscommunication device, a vehicle, a vehicle equipped with an autonomousdriving function, an unmanned aerial vehicle (UAV), an artificialintelligence (AI) module, a robot, an augmented reality (AR) device, avirtual reality (VR) device, and other devices.

For example, a UE may be any of a personal digital assistant (PDA), acellular phone, a personal communication service (PCS) phone, a globalsystem for mobile (GSM) phone, a wideband CDMA (WCDMA) phone, a mobilebroadband system (MBS) phone, a smartphone, and a multi mode-multi band(MINI-MB) terminal.

A smartphone refers to a terminal taking the advantages of both a mobilecommunication terminal and a PDA, which is achieved by integrating adata communication function being the function of a PDA, such asscheduling, fax transmission and reception, and Internet connection in amobile communication terminal. Further, an MINI-MB terminal refers to aterminal which has a built-in multi-modem chip and thus is operable inall of a portable Internet system and other mobile communication system(e.g., CDMA 2000, WCDMA, and so on).

Alternatively, the UE may be any of a laptop PC, a hand-held PC, atablet PC, an ultrabook, a slate PC, a digital broadcasting terminal, aportable multimedia player (PMP), a navigator, and a wearable devicesuch as a smartwatch, smart glasses, and a head mounted display (HMD).For example, a UAV may be an unmanned aerial vehicle that flies underthe control of a wireless control signal. For example, an HMD may be adisplay device worn around the head. For example, the HMD may be used toimplement AR or VR.

Various embodiments of the present disclosure may be implemented invarious means. For example, various embodiments of the presentdisclosure may be implemented in hardware, firmware, software, or acombination thereof.

In a hardware configuration, the methods according to exemplaryembodiments of the present disclosure may be achieved by one or moreApplication Specific Integrated Circuits (ASICs), Digital SignalProcessors (DSPs), Digital Signal Processing Devices (DSPDs),Programmable Logic Devices (PLDs), Field Programmable Gate Arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In a firmware or software configuration, the methods according to thevarious embodiments of the present disclosure may be implemented in theform of a module, a procedure, a function, etc. performing theabove-described functions or operations. A software code may be storedin the memory 50 or 150 and executed by the processor 40 or 140. Thememory is located at the interior or exterior of the processor and maytransmit and receive data to and from the processor via various knownmeans.

Those skilled in the art will appreciate that the various embodiments ofthe present disclosure may be carried out in other specific ways thanthose set forth herein without departing from the spirit and essentialcharacteristics of the various embodiments of the present disclosure.The above embodiments are therefore to be construed in all aspects asillustrative and not restrictive. The scope of the disclosure should bedetermined by the appended claims and their legal equivalents, not bythe above description, and all changes coming within the meaning andequivalency range of the appended claims are intended to be embracedtherein. It is obvious to those skilled in the art that claims that arenot explicitly cited in each other in the appended claims may bepresented in combination as an embodiment of the present disclosure orincluded as a new claim by a subsequent amendment after the applicationis filed.

The various embodiments of present disclosure are applicable to variouswireless access systems including a 3GPP system, and/or a 3GPP2 system.Besides these wireless access systems, the various embodiments of thepresent disclosure are applicable to all technical fields in which thewireless access systems find their applications. Moreover, the proposedmethod can also be applied to mmWave communication using an ultra-highfrequency band.

What is claimed is:
 1. A method of performing a 2-step random accessprocedure by a user equipment (UE) in a wireless communication system,the method comprising: receiving configuration information related to amessage A related to the 2-step random access procedure, wherein themessage A comprises a physical random access channel (PRACH) preamble, aphysical uplink shared channel (PUSCH), and a demodulation referencesignal (DMRS) for the PUSCH; transmitting the message A; and receiving amessage B related to the 2-step random access procedure in response tothe message A, wherein the PUSCH is obtained based on a scramblingsequence related to a random access preamble identifier (RAPID) of thePRACH preamble, wherein the PUSCH is transmitted in at least one PUSCHoccasion among consecutive PUSCH occasions in a frequency domain and atime domain, wherein the consecutive PUSCH occasions are obtained basedon the configuration information, wherein the configuration informationcomprises information regarding a number of physical resource blocks(PRBs) for the consecutive PUSCH occasions, wherein the PRACH preambleis obtained among at least one preconfigured PRACH preamble, wherein theDMRS is related to (i) at least one DMRS port and (ii) at least one DMRSsequence, and wherein the at least one preconfigured PRACH preamble ismapped to (i) the at least one DMRS port and then (ii) the at least oneDMRS sequence based on (i) an index of each of the at least one DMRSport being considered in ascending order and then (ii) an index of eachof the at least one DMRS sequence being considered in ascending order.2. The method of claim 1, wherein the configuration further comprisesinformation related to whether the PUSCH is mapped continuously in thefrequency domain.
 3. The method of claim 1, wherein a maximum number ofDMRS ports is 4 based on the DMRS being configured in one orthogonalfrequency division multiplexing (OFDM) symbol.
 4. The method of claim 1,wherein the PUSCH is transmitted based on a modulation and coding scheme(MCS) level associated with the RAPID.
 5. The method of claim 4, whereinbased on a plurality of frequency resource sets being configured for theDMRS: the DMRS is transmitted based on a frequency resource setassociated with the RAPID among the plurality of frequency resourcesets.
 6. The method of claim 1, wherein the PRACH preamble istransmitted in at least one PRACH occasion among PRACH occasions,wherein the PRACH occasions and the consecutive PUSCH occasions aremultiplexed in time division multiplexing (TDM) based on (i) the PRACHoccasions being included in a first slot for the message A and (ii) thePUSCH occasions being included in a second slot for the message A, andwherein the first slot and the second slot are different.
 7. The methodof claim 6, wherein a time offset is configured between the PRACHoccasions and the consecutive PUSCH occasions in the time domain.
 8. Auser equipment (UE) configured to perform a 2-step random accessprocedure in a wireless communication system, the UE comprising: atransceiver; and at least one processor coupled to the transceiver,wherein the at least one processor is configured to: receiveconfiguration information related to a message A related to the 2-steprandom access procedure, wherein the message A comprises a physicalrandom access channel (PRACH) preamble, a physical uplink shared channel(PUSCH), and a demodulation reference signal (DMRS) for the PUSCH;transmit the message A; and receive a message B related to the 2-steprandom access procedure in response to the message A, wherein the PUSCHis obtained based on a scrambling sequence related to a random accesspreamble identifier (RAPID) of the PRACH preamble, wherein the PUSCH istransmitted in at least one PUSCH occasion among consecutive PUSCHoccasions in a frequency domain and a time domain, wherein theconsecutive PUSCH occasions are obtained based on the configurationinformation, wherein the configuration information comprises informationregarding a number of physical resource blocks (PRBs) for theconsecutive PUSCH occasions, wherein the PRACH preamble is obtainedamong at least one preconfigured PRACH preamble, wherein the DMRS isrelated to (i) at least one DMRS port and (ii) at least one DMRSsequence, and wherein the at least one preconfigured PRACH preamble ismapped to (i) the at least one DMRS port and then (ii) the at least oneDMRS sequence based on (i) an index of each of the at least one DMRSport being considered in ascending order and then (ii) an index of eachof the at least one DMRS sequence being considered in ascending order.9. A method of performing a 2-step random access procedure by a basestation (BS) in a wireless communication system, the method comprising:transmitting configuration information related to a message A related tothe 2-step random access procedure, wherein the message A comprises aphysical random access channel (PRACH) preamble, a physical uplinkshared channel (PUSCH), and a demodulation reference signal (DMRS) forthe PUSCH; receiving the message A; and transmitting a message B relatedto the 2-step random access procedure in response to the message A,wherein the PUSCH is obtained based on a scrambling sequence related toa random access preamble identifier (RAPID) of the PRACH preamble,wherein the PUSCH is received in at least one PUSCH occasion amongconsecutive PUSCH occasions in a frequency domain and a time domain,wherein the consecutive PUSCH occasions are obtained based on theconfiguration information, wherein the configuration informationcomprises information regarding a number of physical resource blocks(PRBs) for the consecutive PUSCH occasions, wherein the PRACH preambleis obtained among at least one preconfigured PRACH preamble, wherein theDMRS is related to (i) at least one DMRS port and (ii) at least one DMRSsequence, and wherein the at least one preconfigured PRACH preamble ismapped to (i) the at least one DMRS port and then (ii) the at least oneDMRS sequence based on (i) an index of each of the at least one DMRSport being considered in ascending order and then (ii) an index of eachof the at least one DMRS sequence being considered in ascending order.10. A base station (BS) configured to perform a 2-step random accessprocedure in a wireless communication system, the BS comprising: atransceiver; and at least one processor coupled to the transceiver,wherein the at least one processor is configured to: transmitconfiguration information related to a message A related to the 2-steprandom access procedure, wherein the message A comprises a physicalrandom access channel (PRACH) preamble, a physical uplink shared channel(PUSCH), and a demodulation reference signal (DMRS) for the PUSCH;receive the message A; and transmit a message B related to the 2-steprandom access procedure in response to the message A, wherein the PUSCHis obtained based on a scrambling sequence related to a random accesspreamble identifier (RAPID) of the PRACH preamble, wherein the PUSCH isreceived in at least one PUSCH occasion among consecutive PUSCHoccasions in a frequency domain and a time domain, wherein theconsecutive PUSCH occasions are obtained based on the configurationinformation, wherein the configuration information comprises informationregarding a number of physical resource blocks (PRBs) for theconsecutive PUSCH occasions, wherein the PRACH preamble is obtainedamong at least one preconfigured PRACH preamble, wherein the DMRS isrelated to (i) at least one DMRS port and (ii) at least one DMRSsequence, and wherein the at least one preconfigured PRACH preamble ismapped to (i) the at least one DMRS port and then (ii) the at least oneDMRS sequence based on (i) an index of each of the at least one DMRSport being considered in ascending order and then (ii) an index of eachof the at least one DMRS sequence being considered in ascending order.